Transmission mechanisms with three gear sets and a stationary gear member

ABSTRACT

The family of transmissions has a plurality of members that can be utilized in powertrains to provide at least seven forward speed ratios and one reverse speed ratio. The transmission family members include three planetary gear sets having six torque-transmitting mechanisms and a fixed interconnection. Also, one planetary gear member is continuously connected with the transmission housing. The powertrain includes an engine and torque converter that is continuously connected to at least one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The six torque-transmitting mechanisms provide interconnections between various gear members, the fixed interconnections, the input shaft, the output shaft, and the transmission housing, and are operated in combinations of three to establish at least seven forward speed ratios and at least one reverse speed ratio.

TECHNICAL FIELD

The present invention relates to a family of power transmissions havingthree planetary gear sets that are controlled by six torque-transmittingdevices to provide at least seven forward speed ratios and one reversespeed ratio.

BACKGROUND OF THE INVENTION

Passenger vehicles include a powertrain that is comprised of an engine,multi-speed transmission, and a differential or final drive. Themulti-speed transmission increases the overall operating range of thevehicle by permitting the engine to operate through its torque range anumber of times. The number of forward speed ratios that are availablein the transmission determines the number of times the engine torquerange is repeated. Early automatic transmissions had two speed ranges.This severely limited the overall speed range of the vehicle andtherefore required a relatively large engine that could produce a widespeed and torque range. This resulted in the engine operating at aspecific fuel consumption point during cruising, other than the mostefficient point. Therefore, manually-shifted (countershafttransmissions) were the most popular.

With the advent of three- and four-speed automatic transmissions, theautomatic shifting (planetary gear) transmission increased in popularitywith the motoring public. These transmissions improved the operatingperformance and fuel economy of the vehicle. The increased number ofspeed ratios reduces the step size between ratios and therefore improvesthe shift quality of the transmission by making the ratio interchangessubstantially imperceptible to the operator under normal vehicleacceleration.

It has been suggested that the number of forward speed ratios beincreased to six or more. Six-speed transmissions are disclosed in U.S.Pat. No. 4,070,927 issued to Polak on Jan. 31, 1978; U.S. Pat. No.6,071,208 issued to Koivunen on Jun. 6, 2000; U.S. Pat. No. 5,106,352issued to Lepelletier on Apr. 21, 1992; and U.S. Pat. No. 5,599,251issued to Beim and McCarrick on Feb. 4, 1997.

Six-speed transmissions offer several advantages over four- andfive-speed transmissions, including improved vehicle acceleration andimproved fuel economy. While many trucks employ power transmissionshaving six or more forward speed ratios, passenger cars are stillmanufactured with three- and four-speed automatic transmissions andrelatively few five or six-speed devices due to the size and complexityof these transmissions. The Polak transmission provides six forwardspeed ratios with three planetary gear sets, two clutches, and threebrakes. The Koivunen and Beim patents utilize six torque-transmittingdevices including four brakes and two clutches to establish six forwardspeed ratios and a reverse ratio. The Lepelletier patent employs threeplanetary gear sets, three clutches and two brakes to provide sixforward speeds. One of the planetary gear sets is positioned andoperated to establish two fixed speed input members for the remainingtwo planetary gear sets.

Seven-speed transmissions are disclosed in U.S. Pat. No. 4,709,594 toMaeda; U.S. Pat. No. 6,053,839 to Baldwin et. al.; and U.S. Pat. No.6,083,135 to Baldwin et. al. Seven- and eight-speed transmissionsprovide further improvements in acceleration and fuel economy oversix-speed transmissions. However, like the six-speed transmissionsdiscussed above, the development of seven- and eight-speed transmissionshas been precluded because of complexity, size and cost.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved familyof transmissions having three planetary gear sets controlled to provideat least seven forward speed ratios and one reverse speed ratio.

In one aspect of the present invention, the family of transmissions hasthree planetary gear sets, each of which includes a first, second andthird member, which members may comprise a sun gear, a ring gear, or aplanet carrier assembly member.

In referring to the first, second and third gear sets in thisdescription and in the claims, these sets may be counted “first” to“third” in any order in the drawings (i.e., left to right, right toleft, etc.).

In another aspect of the present invention, each of the planetary gearsets may be of the single pinion-type or of the double pinion-type.

In yet another aspect of the present invention, the first member of thefirst planetary gear set is continuously interconnected to the firstmember of the second planetary gear set through an interconnectingmember.

In yet another aspect of the present invention, the first member of thethird planetary gear set is continuously interconnected with astationary member (transmission housing).

In yet a further aspect of the invention, each family memberincorporates an input shaft which is continuously connected with amember of the planetary gear sets and an output shaft which iscontinuously connected with another member of the planetary gear sets.

In still a further aspect of the invention, a first torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thefirst planetary gear set with a member of the second or third planetarygear set.

In another aspect of the invention, a second torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thesecond planetary gear set with a member of the first or third planetarygear set.

In a still further aspect of the invention, a third torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thethird planetary gear set with a member of the first or second planetarygear set.

In a still further aspect of the invention, a fourth torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thefirst or second planetary gear set with another member of the first,second or third planetary gear set.

In a still further aspect of the invention, a fifth torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thesecond or third planetary gear set with another member of the first,second or third planetary gear set. Alternatively, the fifthtorque-transmitting mechanism, such as a brake, selectivelyinterconnects a member of the first, second or third planetary gear setwith the stationary member (transmission housing).

In still another aspect of the invention, a sixth torque-transmittingmechanism, such as a clutch, selectively interconnects a member of thefirst or third planetary gear set with another member of the first,second or third planetary gear set. Alternatively, the sixthtorque-transmitting mechanism, such as a brake, selectively connects amember of the first, second or third planetary gear set with thestationary member (transmission case).

In still another aspect of the invention, the six torque-transmittingmechanisms are selectively engageable in combinations of three to yieldat least seven forward speed ratios and at least one reverse speedratio.

The above objects and other objects, features, and advantages of thepresent invention are readily apparent from the following detaileddescription of the best modes for carrying out the invention when takenin connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is a schematic representation of a powertrain including aplanetary transmission incorporating a family member of the presentinvention;

FIG. 1b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 1a;

FIG. 2a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 2b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 2a;

FIG. 3a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 3b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 3a;

FIG. 4a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 4b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 4a;

FIG. 5a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 5b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 5a;

FIG. 6a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 6b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 6a;

FIG. 7a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 7b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 7a;

FIG. 8a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 8b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 8a;

FIG. 9a is a schematic representation of a powertrain having a planetarytransmission incorporating another family member of the presentinvention;

FIG. 9b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 9a;

FIG. 10a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 10b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 10a;

FIG. 11a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 11b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 11a;

FIG. 12a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 12b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 12a;

FIG. 13a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 13b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 13a;

FIG. 14a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 14b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 14a;

FIG. 15a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 15b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 15a;

FIG. 16a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 16b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 16a;

FIG. 17a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 17b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 17a;

FIG. 18a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 18b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 18a;

FIG. 19a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention;

FIG. 19b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 19a;

FIG. 20a is a schematic representation of a powertrain having aplanetary transmission incorporating another family member of thepresent invention; and

FIG. 20b is a truth table and chart depicting some of the operatingcharacteristics of the powertrain shown in FIG. 20a.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, wherein like characters represent the same orcorresponding parts throughout the several views, there is shown in FIG.1a a powertrain 10 having a conventional engine and torque converter 12,a planetary transmission 14, and a conventional final drive mechanism16.

The planetary transmission 14 includes an input shaft 17 continuouslyconnected with the engine and torque converter 12, a planetary geararrangement 18, and an output shaft 19 continuously connected with thefinal drive mechanism 16. The planetary gear arrangement 18 includesthree planetary gear sets 20, 30 and 40.

The planetary gear set 20 includes a sun gear member 22, a ring gearmember 24, and a planet carrier assembly 26. The planet carrier assembly26 includes a plurality of pinion gears 27 rotatably mounted on acarrier member 29 and disposed in meshing relationship with both the sungear member 22 and the ring gear member 24.

The planetary gear set 30 includes a sun gear member 32, a ring gearmember 34, and a planet carrier assembly member 36. The planet carrierassembly member 36 includes a plurality of pinion gears 37 rotatablymounted on a carrier member 39 and disposed in meshing relationship withboth the sun gear member 32 and the ring gear member 34.

The planetary gear set 40 includes a sun gear member 42, a ring gearmember 44, and a planet carrier assembly member 46. The planet carrierassembly member 46 includes a plurality of pinion gears 47 rotatablymounted on a carrier member 49 and disposed in meshing relationship withboth the sun gear member 42 and the ring gear member 44.

The planetary gear arrangement also includes six torque-transmittingmechanisms 50, 52, 54, 56, 58 and 59. The torque-transmitting mechanisms50, 52, 54 and 56 are rotating-type torque-transmitting mechanisms,commonly termed clutches. The torque-transmitting mechanisms 58 and 59are stationary-type torque transmitting mechanisms, commonly termedbrakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member22, and the output shaft 19 is continuously connected with the sun gearmember 32. The planet carrier assembly member 26 is continuouslyconnected with the ring gear member 34 through the interconnectingmember 70. The sun gear member 42 is continuously connected with thetransmission housing 60.

The ring gear member 34 is selectively connectable with the ring gearmember 44 through the clutch 50. The ring gear member 24 is selectivelyconnectable with the planet carrier assembly member 46 through theclutch 52. The sun gear member 22 is selectively connectable with theplanet carrier assembly member 36 through the clutch 54. The sun gearmember 32 is selectively connectable with the planet carrier assemblymember 46 through the clutch 56. The planet carrier assembly member 26is selectively connectable with the transmission housing 60 through thebrake 58. The ring gear member 24 is selectively connectable with thetransmission 60 through the brake 59.

As shown in FIG. 1b, and in particular the truth table disclosedtherein, the torque-transmitting mechanisms are selectively engaged incombinations of three to provide seven forward speed ratios and areverse speed ratio.

The reverse speed ratio is established via engagement of the clutches52, 56 and the brake 58. The clutch 52 connects with the ring gearmember 24 to the planet carrier assembly member 46. The clutch 54connects the sun gear member 32 to the planet carrier assembly member46. The brake 58 connects the planet carrier assembly member 26 to thetransmission housing 60. The sun gear member 22 rotates at the samespeed as the input shaft 17. The planet carrier assembly member 26 andthe ring gear member 34 do not rotate. The ring gear member 24, planetcarrier assembly member 46 and the sun gear member 32 rotate at the samespeed as the output shaft 19. The ring gear member 24, and therefore theoutput shaft 19, rotates at a speed determined from the speed of the sungear member 22 and ring gear/sun gear tooth ratio of the planetary gearset 20. The sun gear member 42 does not rotate. The numerical value ofthe reverse speed ratio is determined utilizing the ring gear/sun geartooth ratio of the planetary gear set 20.

The first forward speed ratio is established with the engagement of theclutches 50, 56 and the brake 59. The clutch 50 connects the ring gearmember 34 to the ring gear member 44. The clutch 56 connects the sungear member 32 to the planet carrier assembly member 46. The brake 59connects the ring gear member 24 to the transmission housing 60. The sungear member 22 rotates at the same speed as the input shaft 17. Theplanet carrier assembly member 26 rotates at the same speed as the ringgear member 34, 44. The ring gear member 24 does not rotate. The planetcarrier assembly member 26 rotates at a speed determined from the speedof the sun gear member 22 and the ring gear/sun gear tooth ratio of theplanetary gear set 20. The sun gear member 32 and the planet carrierassembly member 46 rotate at the same speed as the output shaft 19. Thesun gear member 42 does not rotate. The planet carrier assembly member46, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the ring gear member 44 and the ring gear/sun geartooth ratio of the planetary gear set 40. The numerical value of thefirst forward speed ratio is determined utilizing the ring gear/sun geartooth ratios of the planetary gear set 20, 40.

The second forward speed ratio is established with the engagement of theclutches 50, 52 and 56. The clutch 50 connects the ring gear member 34to the ring gear member 44. The clutch 52 connects the ring gear member24 to the planet carrier assembly member 46. The clutch 56 connects thesun gear member 32 to the planet carrier assembly member 46. The sungear member 22 rotates at the same speed as the input shaft 17. Theplanet carrier assembly member 26 rotates at the same speed as the ringgear members 34, 44. The ring gear member 24, the planet carrierassembly member 46 and the sun gear member 32 rotate at the same speedas the output shaft 19. The planet carrier assembly member 26 rotates ata speed determined from the speed of the ring gear member 24, the speedof the sun gear member 22, and the ring gear/sun gear tooth ratio of theplanetary gear set 20. The sun gear member 42 does not rotate. Theplanet carrier assembly member 46, and therefore the output shaft 19,rotates at a speed determined from the speed of the ring gear member 44and the ring gear/sun gear tooth ratio of the planetary gear set 40. Thenumerical value of the second forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets20, 40.

The third forward speed ratio is established with the engagement of theclutches 50, 54 and 56. The clutch 50 connects the ring gear member 34to the ring gear member 44. The clutch 54 connects the sun gear member22 to the planet carrier assembly member 36. The clutch 56 connects thesun gear member 32 to the planet carrier assembly member 46. The sungear member 22 and planet carrier assembly member 36 rotate at the samespeed as the input shaft 17. The planet carrier assembly member 26rotates at the same speed as the ring gear member 34, 44. The sun gearmember 32 and the planet carrier assembly member 46 rotate at the samespeed as the output shaft 19. The sun gear member 32, and therefore theoutput shaft 19, rotates at a speed determined from the speed of thering gear member 34, the speed of the planet carrier assembly member 36and the ring gear/sun gear tooth ratio of the planetary gear set 30. Thesun gear member 42 does not rotate. The planet carrier assembly member46 rotates at a speed determined from the speed of the ring gear member44 and the ring gear/sun gear tooth ratio of the planetary gear set 40.The numerical value of the third forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets20, 30.

The fourth forward speed ratio is established with the engagement of theclutches 52, 54 and 56. In this configuration, the input shaft 17 isdirectly connected to the output shaft 19. The numerical value of thefourth forward speed ratio is one.

The fifth forward speed ratio is established with the engagement of theclutches 50, 52 and 54. The clutch 50 connects the ring gear member 34to the ring gear member 44. The clutch 52 connects the ring gear member24 to the planet carrier assembly member 46. The clutch 54 connects thesun gear member 22 to the planet carrier assembly member 36. The sungear member 22 and the planet carrier assembly member 36 rotate at thesame speed as the input shaft 17. The planet carrier assembly member 26rotates at the same speed as the ring gear member 34, 44. The ring gearmember 24 rotates at the same speed as the planet carrier assemblymember 46. The planet carrier assembly member 26 rotates at a speeddetermined from the speed of the ring gear member 24, the speed of thesun gear member 22, and the ring gear/sun gear tooth ratio of theplanetary gear set 20. The sun gear member 32 rotates at the same speedas the output shaft 19. The sun gear member 32, and therefore the outputshaft 19, rotates at a speed determined from the speed of the ring gearmember 34, the speed of the planet carrier assembly member 36 and thering gear/sun gear tooth ratio of the planetary gear set 30. The sungear member 42 does not rotate. The planet carrier assembly member 46rotates at a speed determined from the speed of the ring gear member 44and the ring gear/sun gear tooth ratio of the planetary gear set 40. Thenumerical value of the fifth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear set 20, 30 and40.

The sixth forward speed ratio is established with the engagement of theclutches 52, 54 and the brake 59. The clutch 52 connects the ring gearmember 24 to the planet carrier assembly member 46. The clutch 54connects the sun gear member 22 to the planet carrier assembly member36. The brake 59 connects the ring gear member 24 to the transmissionhousing 60. The sun gear member 22 and the planet carrier assemblymember 36 rotate at the same speed as the input shaft 17. The planetcarrier assembly member 26 rotates at the same speed as the ring gearmember 34. The ring gear member 24 and the planetary gear set 40 do notrotate. The planet carrier assembly member 26 rotates at a speeddetermined from the speed of the sun gear member 22 and the ringgear/sun gear tooth ratio of the planetary gear set 20. The sun gearmember 32 rotates at the same speed as the output shaft 19. The sun gearmember 32, and therefore the output shaft 19, rotates at a speeddetermined from the speed of the planet carrier assembly member 36, thespeed of the ring gear member 34 and the ring gear/sun gear tooth ratioof the planetary gear set 30. The numerical value of the sixth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 20, 30.

The seventh forward speed ratio is established with the engagement ofthe clutches 52, 54 and the brake 58. The clutch 52 connects the ringgear member 24 to the planet carrier assembly member 46. The clutch 54connects the sun gear member 22 to the planet carrier assembly member36. The brake 58 connects the planet carrier assembly member 26 to thetransmission housing 60. The sun gear member 22 and the planet carrierassembly member 36 rotate at the same speed as the input shaft 17. Theplanet carrier assembly member 26 and the ring gear member 34 do notrotate. The ring gear member 24 rotates at the same speed as the planetcarrier assembly member 46. The sun gear member 32 rotates at the samespeed as the output shaft 19. The sun gear member 32, and therefore theoutput shaft 19, rotates at a speed determined from the speed of theplanet carrier assembly member 36 and the ring gear/sun gear tooth ratioof the planetary gear set 30. The sun gear member 42 does not rotate.The numerical value of the seventh forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set30.

As set forth above, the engagement schedule for the torque-transmittingmechanisms is shown in the truth table of FIG. 1b. This truth table alsoprovides an example of speed ratios that are available utilizing thering gear/sun gear tooth ratios given by way of example in FIG. 1b. TheR1/S1 value is the tooth ratio of the planetary gear set 20; the R2/S2value is the tooth ratio of the planetary gear set 30; and the R3/S3value is the tooth ratio of the planetary gear set 40. Also, the chartof FIG. 1b describes the ratio steps that are attained utilizing thesample of tooth ratios given. For example, the step ratio between thefirst and second forward speed ratios is 1.74, while the step ratiobetween the reverse and first forward ratio is −0.42. It can also bereadily determined from the truth table of FIG. 1b that all of thesingle step forward ratio interchanges are of the single transitionvariety, except the reverse to first step. The double step forwardinterchanges are of the single transition variety as well.

FIG. 2a shows a powertrain 110 having a conventional engine and torqueconverter 12, a planetary transmission 114, and a conventional finaldrive mechanism 16.

The planetary transmission 114 includes an input shaft 17 continuouslyconnected with the engine and torque converter 12, a planetary geararrangement 118, and an output shaft 19 continuously connected with thefinal drive mechanism 16. The planetary gear arrangement 118 includesthree planetary gear sets 120, 130 and 140.

The planetary gear set 120 includes a sun gear member 122, a ring gearmember 124, and a planet carrier assembly 126. The planet carrierassembly 126 includes a plurality of pinion gears 127 rotatably mountedon a carrier member 129 and disposed in meshing relationship with boththe sun gear member 122 and the ring gear member 124.

The planetary gear set 130 includes a sun gear member 132, a ring gearmember 134, and a planet carrier assembly member 136. The planet carrierassembly member 136 includes a plurality of pinion gears 137 rotatablymounted on a carrier member 139 and disposed in meshing relationshipwith both the sun gear member 132 and the ring gear member 134.

The planetary gear set 140 includes a sun gear member 142, a ring gearmember 144, and a planet carrier assembly member 146. The planet carrierassembly member 146 includes a plurality of pinion gears 147 rotatablymounted on a carrier member 149 and disposed in meshing relationshipwith both the sun gear member 142 and the ring gear member 144.

The planetary gear arrangement 118 also includes six torque-transmittingmechanisms 150, 152, 154, 156, 158 and 159. The torque-transmittingmechanisms 150, 152, 154, 156 and 158 are rotating-typetorque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanism 159 is a stationary-type torquetransmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the planet carrierassembly member 136, and the output shaft 19 is continuously connectedwith the sun gear member 132. The ring gear member 124 is continuouslyconnected with the planet carrier assembly member 136 through theinterconnecting member 170. The ring gear member 144 is continuouslyconnected with the transmission housing 160.

The planet carrier assembly member 126 is selectively connectable withthe planet carrier assembly member 146 through the clutch 150. Theplanet carrier assembly member 126 is selectively connectable with thesun gear member 142 through the clutch 152. The ring gear member 134 isselectively connectable with the planet carrier assembly member 146through the clutch 154. The ring gear member 134 is selectivelyconnectable with the sun gear member 142 through the clutch 156. The sungear member 132 is selectively connectable with the planet carrierassembly member 146 through the clutch 158. The sun gear member 122 isselectively connectable with the transmission housing 160 through thebrake 159.

The truth table of FIG. 2b describes the engagement sequence utilized toprovide seven forward speed ratios and a reverse speed ratio in theplanetary gear arrangement 118 shown in FIG. 2a.

The reverse speed ratio is established with the engagement of theclutches 150, 156 and the brake 159. The clutch 150 connects the planetcarrier assembly member 126 to planet carrier assembly member 146. Theclutch 156 connects the ring gear member 134 to the sun gear member 142.The brake 159 connects the sun gear member 122 to the transmissionhousing 160. The sun gear member 122 does not rotate. The planet carrierassembly members 126 and 146 rotate at the same speed. The ring gearmember 124 and the planet carrier assembly member 136 rotate at the samespeed as the input shaft 17. The planet carrier assembly member 126rotates at a speed determined from the speed of the ring gear member 124and the ring gear/sun gear tooth ratio of the planetary gear set 120.The ring gear member 134 rotates at the same speed as the sun gearmember 142. The sun gear member 132 rotates at the same speed as theoutput shaft 19. The sun gear member 132, and therefore the output shaft19, rotates at a speed determined from the speed of the ring gear member134, the speed of the planet carrier assembly member 136 and the ringgear/sun gear tooth ratio of the planetary gear set 130. The ring gearmember 144 does not rotate. The planet carrier assembly member 146rotates at a speed determined from the speed of the sun gear member 142and the ring gear/sun gear tooth ratio of the planetary gear set 140.The numerical value of the reverse speed ratio is determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 120, 130and 140.

The first forward speed ratio is established with the engagement of theclutches 152, 158 and the brake 159. The clutch 152 connects the planetcarrier assembly member 126 to the sun gear member 142. The clutch 158connects the sun gear member 132 to the planet carrier assembly member146. The brake 159 connects the sun gear member 122 to the transmissionhousing 160. The sun gear member 122 does not rotate. The planet carrierassembly member 126 rotates at the same speed as the sun gear member142. The ring gear member 124 and the planet carrier assembly member 136rotate at the same speed as the input shaft 17. The planet carrierassembly member 126 rotates at a speed determined from the speed of thering gear member 124 and the ring gear/sun gear tooth ratio of theplanetary gear set 120. The sun gear member 132 and the planet carrierassembly member 146 rotate at the same speed as the output shaft 19. Thering gear member 144 does not rotate. The planet carrier assembly member146, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the sun gear member 142 and the ring gear/sun geartooth ratio of the planetary gear set 140. The numerical value of thefirst forward speed ratio is determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 120, 140.

The second forward speed ratio is established with the engagement of theclutches 156, 158 and the brake 159. The clutch 156 connects the ringgear member 134 to the sun gear member 142. The clutch 158 connects thesun gear member 132 to the planet carrier assembly member 146. The brake159 connects the sun gear member 122 to the transmission housing 160.The sun gear member 122 does not rotate. The ring gear member 124 andthe planet carrier assembly member 136 rotate at the same speed as theinput shaft 17. The ring gear member 134 rotates at the same speed asthe sun gear member 142. The sun gear member 132 and the planet carrierassembly member 146 rotate at the same speed as the output shaft 19. Thesun gear member 132, and therefore the output shaft 19, rotates at aspeed determined from the speed of the ring gear member 134, the speedof the planet carrier assembly member 136 and the ring gear/sun geartooth ratio of the planetary gear set 130. The ring gear member 144 doesnot rotate. The planet carrier assembly member 146 rotates at a speeddetermined from the speed of the sun gear member 142 and the ringgear/sun gear tooth ratio of the planetary gear set 140. The numericalvalue of the second forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 130 and 140.

The third forward speed ratio is established with the engagement of theclutches 150, 158 and the brake 159. The clutch 150 connects the planetcarrier assembly member 126 to the planet carrier assembly member 146.The clutch 158 connects the sun gear member 132 to the planet carrierassembly member 146. The brake 159 connects sun gear member 122 to thetransmission housing 160. The sun gear member 122 does not rotate. Theplanet carrier assembly members 126, 146 and the sun gear member 132rotate at the same speed as the output shaft 19. The ring gear member124 and the planet carrier assembly member 136 rotate at the same speedas the input shaft 17. The planet carrier assembly member 126, andtherefore the output shaft 19, rotates at a speed determined from thespeed of the ring gear member 124 and the ring gear/sun gear tooth ratioof the planetary gear set 120. The ring gear member 144 does not rotate.The numerical value of the third forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set120.

The fourth forward speed ratio is established with the engagement of theclutches 154, 158 and the brake 159. In this configuration, the inputshaft 17 is directly connected to the output shaft 19. The numericalvalue of the fourth forward speed ratio is one.

The fifth forward speed ratio is established with the engagement of theclutches 150, 154 and the brake 159. The clutch 150 connects the planetcarrier assembly member 126 to planet carrier assembly member 146. Theclutch 154 connects the ring gear member 134 to the planet carrierassembly member 146. The brake 159 connects the sun gear member 122 tothe transmission housing 160. The sun gear member 122 does not rotate.The planet carrier assembly members 126, 146 rotate at the same speed asthe ring gear member 134. The ring gear member 124 and the planetcarrier assembly member 136 rotate at the same speed as the input shaft17. The planet carrier assembly member 126 rotates at a speed determinedfrom the speed of the ring gear member 124 and the ring gear/sun geartooth ratio of the planetary gear set 120. The sun gear member 132rotates at the same speed as the output shaft 19. The sun gear member132, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the ring gear member 134, the speed of the planetcarrier assembly member 136 and the ring gear/sun gear tooth ratio ofplanetary gear set 130. The ring gear member 144 does not rotate. Thenumerical value of the fifth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 120, 130.

The sixth forward speed ratio is established with the engagement of theclutches 152, 154 and the brake 159. The clutch 152 connects the planetcarrier assembly member 126 to the sun gear member 142. The clutch 154connects the ring gear member 134 to the planet carrier assembly member146. The brake 159 connects the sun gear member 122 to the transmissionhousing 160. The sun gear member 122 does not rotate. The planet carrierassembly member 126 rotates at the same speed as the sun gear member142. The ring gear member 124 and the planet carrier assembly member 136rotate at the same speed as the input shaft 17. The planet carrierassembly member 126 rotates at a speed determined from the speed of thering gear member 124 and the ring gear/sun gear tooth ratio of theplanetary gear set 120. The ring gear member 134 rotates at the samespeed as the planet carrier assembly member 146. The sun gear member 132rotates at the same speed as the output shaft 19. The sun gear member132, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the ring gear member 134, the speed of the planetcarrier assembly member 136 and the ring gear/sun gear tooth ratio ofthe planetary gear set 130. The ring gear member 144 does not rotate.The planet carrier assembly member 146 rotates at a speed determinedfrom the speed of the sun gear member 142 and the ring gear/sun geartooth ratio of the planetary gear set 140. The numerical value of thesixth forward speed ratio is determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 120, 130 and 140.

The seventh forward speed ratio is established with the engagement ofthe clutches 150, 152 and 154. The clutch 150 connects the planetcarrier assembly member 126 to the planet carrier assembly member 146.The clutch 152 connects the planet carrier assembly member 126 to thesun gear member 142. The clutch 154 connects the ring gear member 134 tothe planet carrier assembly member 146. The planet carrier assemblymember 126, the ring gear member 134, the planet carrier assembly member146 and the sun gear member 142 rotate at the same speed. The ring gearmember 124 and the planet carrier assembly member 136 rotate at the samespeed as the input shaft 17. The sun gear member 132 rotates at the samespeed as the output shaft 19. The sun gear member 132, and therefore theoutput shaft 19, rotates at a speed determined from the speed of thering gear member 134, the speed of the planet carrier assembly member136 and the ring gear/sun gear tooth ratio of the planetary gear set130. The ring gear member 144 does not rotate. The numerical value ofthe seventh forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 130.

As set forth above, the truth table of FIG. 2b describes the engagementsequence of the torque-transmitting mechanisms utilized to provide areverse drive ratio and seven forward speed ratios. The truth table alsoprovides an example of the ratios that can be attained with the familymembers shown in FIG. 2a utilizing the sample tooth ratios given in FIG.2b. The R1/S1 value is the tooth ratio of the planetary gear set 120;the R2/S2 value is the tooth ratio of the planetary gear set 130; andthe R3/S3 value is the tooth ratio of the planetary gear set 140. Alsoshown in FIG. 2b are the ratio steps between single step ratios in theforward direction as well as the reverse to first ratio step ratio. Forexample, the first to second step ratio is 1.94.

Turning to FIG. 3a, a powertrain 210 includes the engine and torqueconverter 12, a planetary transmission 214, and a final drive mechanism16. The planetary transmission 214 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 218, and an output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 218 includes three planetary gear sets 220, 230 and 240.

The planetary gear set 220 includes a sun gear member 222, a ring gearmember 224, and a planet carrier assembly 226. The planet carrierassembly 226 includes a plurality of pinion gears 227 rotatably mountedon a carrier member 229 and disposed in meshing relationship with boththe sun gear member 222 and the ring gear member 224.

The planetary gear set 230 includes a sun gear member 232, a ring gearmember 234, and a planet carrier assembly member 236. The planet carrierassembly member 236 includes a plurality of pinion gears 237 rotatablymounted on a carrier member 239 and disposed in meshing relationshipwith both the sun gear member 232 and the ring gear member 234.

The planetary gear set 240 includes a sun gear member 242, a ring gearmember 244, and a planet carrier assembly member 246. The planet carrierassembly member 246 includes a plurality of pinion gears 247 rotatablymounted on a carrier member 249 and disposed in meshing relationshipwith both the sun gear member 242 and the ring gear member 244.

The planetary gear arrangement 218 also includes six torque-transmittingmechanisms 250, 252, 254, 256, 258 and 259. The torque-transmittingmechanisms 250, 252, 254, 256 and 258 are rotating typetorque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanism 259 is a stationary-type torquetransmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member222, and the output shaft 19 is continuously connected with the planetcarrier assembly member 236. The sun gear member 222 is continuouslyconnected with the ring gear member 234 through the interconnectingmember 270. The sun gear member 242 is continuously connected with thetransmission housing 260.

The ring gear member 224 is selectively connectable with the planetcarrier assembly member 236 through the clutch 250. The ring gear member224 is selectively connectable with the planet carrier assembly member246 through the clutch 252. The planet carrier assembly member 226 isselectively connectable with the planet carrier assembly member 246through the brake 254. The sun gear member 232 is selectivelyconnectable with the planet carrier assembly member 246 through theclutch 256. The sun gear member 232 is selectively connectable with thering gear member 244 through the clutch 258. The planet carrier assemblymember 226 is selectively connectable with the transmission housing 260through the brake 259.

As shown in the truth table in FIG. 3b, the torque-transmittingmechanisms are engaged in combinations of three to establish sevenforward speed ratios and one reverse ratio.

The reverse speed ratio is established with the engagement of theclutches 250, 258 and the brake 259. The clutch 250 connects the ringgear member 224 to the planet carrier assembly member 236. The clutch258 connects the sun gear member 232 to the ring gear member 244. Thebrake 259 connects the planet carrier assembly member 226 to thetransmission housing 260. The sun gear member 222 and the ring gearmember 234 rotate at the same speed as the input shaft 17. The planetcarrier assembly member 226 does not rotate. The ring gear member 224and the planet carrier assembly member 236 rotate at the same speed asthe output shaft 19. The ring gear member 224, and therefore the outputshaft 19, rotates at a speed determined from the speed of the sun gearmember 222 and the ring gear/sun gear tooth ratio of the planetary gearset 220. The sun gear member 232 rotates at the same speed as the ringgear member 244. The sun gear member 242 does not rotate. The numericalvalue of the reverse speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 220.

The first forward speed ratio is established with the engagement of theclutches 252, 258 and the brake 259. The clutch 252 connects the ringgear member 224 to the planet carrier assembly member 246. The clutch258 connects the sun gear member 232 to the ring gear member 244. Thebrake 259 connects the planet carrier assembly member 226 to thetransmission housing 260. The sun gear member 222 and the ring gearmember 234 rotate at the same speed as the input shaft 17. The planetcarrier assembly member 226 does not rotate. The ring gear member 224rotates at the same speed as the planet carrier assembly member 246. Thering gear member 224 rotates at a speed determined from the speed of thesun gear member 222 and the ring gear/sun gear tooth ratio of theplanetary gear set 220. The planet carrier assembly member 236 rotatesat the same speed as the output shaft 19. The sun gear member 232rotates at the same speed as the ring gear member 244. The planetcarrier assembly member 236, and therefore the output shaft 19, rotatesat a speed determined from the speed of the ring gear member 234, thespeed of the sun gear member 232 and the ring gear/sun gear tooth ratioof the planetary gear set 230. The sun gear member 242 does not rotate.The planet carrier assembly member 246 rotates at a speed determinedfrom the speed of the ring gear member 244 and the ring gear/sun geartooth ratio of the planetary gear set 240. The numerical value of thefirst forward speed ratio is determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 220, 230 and 240.

The second forward speed ratio is established with the engagement of theclutches 252, 256 and the brake 259. The clutch 252 connects the ringgear member 224 to the planet carrier assembly member 246. The clutch256 connects the sun gear member 232 to the planet carrier assemblymember 246. The brake 259 connects the planet carrier assembly member226 to the transmission housing 260. The sun gear member 222 and thering gear member 234 rotate at the same speed as the input shaft 17. Theplanet carrier assembly member 226 does not rotate. The ring gear member224 and the planet carrier assembly member 246 rotate at the same speedas the sun gear member 232. The ring gear member 224 rotates at a speeddetermined from the speed of the sun gear member 222 and the ringgear/sun gear tooth ratio of the planetary gear set 220. The planetcarrier assembly member 236 rotates at the same speed as the outputshaft 19. The planet carrier assembly member 236, and therefore theoutput shaft 19, rotates at a speed determined from the speed of thering gear member 234, the speed of the sun gear member 232 and the ringgear/sun gear tooth ratio of the planetary gear set 230. The sun gearmember 242 does not rotate. The numerical value of the second forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 220, 230.

The third forward speed ratio is established with the engagement of theclutches 254, 256 and the brake 259. The clutch 254 connects the planetcarrier assembly member 226 to the planet carrier assembly member 246.The clutch 256 connects the sun gear member 232 to the planet carrierassembly member 246. The brake 259 connects the planet carrier assemblymember 226 to the transmission housing 260. The sun gear member 222 andthe ring gear member 234 rotate at the same speed as the input shaft 17.The planet carrier assembly members 226, 246 and the sun gear member 232do not rotate. The planet carrier assembly member 236 rotates at thesame speed as the output shaft 19. The planet carrier assembly member236, and therefore the output shaft 19, rotates at a speed determinedfrom the speed of the ring gear member 234 and the ring gear/sun geartooth ratio of the planetary gear set 230. The sun gear member 242 doesnot rotate. The numerical value of the third forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 230.

The fourth forward speed ratio is established with the engagement of theclutches 252, 254 and 256. In this configuration, the input shaft 17 isdirectly connected to the output shaft 19. The numerical value of thefourth forward speed ratio is one.

The fifth forward speed ratio is established with the engagement of theclutches 252, 254 and 258. The clutch 252 connects the ring gear member224 to the planet carrier assembly member 246. The clutch 254 connectsthe planet carrier assembly member 226 to the planet carrier assemblymember 246. The clutch 258 connects the sun gear member 232 to the ringgear member 244. The sun gear member 222 and the ring gear member 234rotate at the same speed as the input shaft 17. The ring gear member 224rotates at the same speed as the planet carrier assembly members 226,246. The planet carrier assembly member 236 rotates at the same speed asthe output shaft 19. The sun gear member 232 rotates at the same speedas the ring gear member 244. The planet carrier assembly member 236, andtherefore the output shaft 19, rotates at a speed determined from thespeed of the ring gear member 234, the speed of the sun gear member 232and the ring gear/sun gear tooth ratio of the planetary gear set 230.The sun gear member 242 does not rotate. The ring gear member 244rotates at a speed determined from the speed of the planet carrierassembly member 246 and the ring gear/sun gear tooth ratio of theplanetary gear set 240. The numerical value of the fifth forward speedratio is determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 230 and 240.

The sixth forward speed ratio is established with the engagement of theclutches 250, 254 and 258. The clutch 250 connects the ring gear member224 to the planet carrier assembly member 236. The clutch 254 connectsthe planet carrier assembly member 226 to the planet carrier assemblymember 246. The clutch 258 connects the sun gear member 232 to the ringgear member 244. The sun gear member 222 and the ring gear member 234rotate at the same speed as the input shaft 17. The planet carrierassembly member 226 rotates at the same speed as the planet carrierassembly member 246. The ring gear member 224 and the planet carrierassembly member 236 rotate at the same speed as the output shaft 19. Theplanet carrier assembly member 226 rotates at a speed determined fromthe speed of the ring gear member 224, the speed of the sun gear member222 and the ring gear/sun gear tooth ratio of the planetary gear set220. The sun gear member 232 rotates at the same speed as the ring gearmember 244. The planet carrier assembly member 236, and therefore theoutput shaft 19, rotates at a speed determined from the speed of thering gear member 234, the speed of the sun gear member 232 and the ringgear/sun gear tooth ratio of the planetary gear set 230. The sun gearmember 242 does not rotate. The planet carrier assembly member 246rotates at a speed determined from the speed of the ring gear member 244and the ring gear/sun gear tooth ratio of the planetary gear set 240.The numerical value of the sixth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets220, 230 and 240.

The seventh forward speed ratio is established with the engagement ofthe clutches 250, 252 and 258. The clutch 250 connects the ring gearmember 224 to the planet carrier assembly member 236. The clutch 252connects the ring gear member 224 to the planet carrier assembly member246. The clutch 258 connects the sun gear member 232 to the ring gearmember 244. The sun gear member 222 and the ring gear member 234 rotateat the same speed as the input shaft 17. The ring gear member 224 andthe planet carrier assembly members 236, 246 rotate at the same speed asthe output shaft 19. The sun gear member 232 rotates at the same speedas the ring gear member 244. The planet carrier assembly member 236, andtherefore the output shaft 19, rotates at a speed determined from thespeed of the ring gear member 234, the speed of the sun gear member 232and the ring gear/sun gear tooth ratio of the planetary gear set 230.The sun gear member 242 does not rotate. The planet carrier assemblymember 246 rotates at a speed determined from the speed of the ring gearmember 244 and the ring gear/sun gear tooth ratio of the planetary gearset 240. The numerical value of the seventh forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear set 230, 240.

As previously set forth, the truth table of FIG. 3b describes thecombinations of engagements utilized for the seven forward speed ratiosand reverse ratio. The truth table also provides an example of speedratios that are available with the family member described above. Theseexamples of speed ratios are determined utilizing the tooth ratios givenin FIG. 3b. The R1/S1 value is the tooth ratio of the planetary gear set220; the R2/S2 value is the tooth ratio of the planetary gear set 230;and the R3/S3 value is the tooth ratio of the planetary gear set 240.Also depicted in FIG. 3b is a chart representing the ratio steps betweenadjacent forward speed ratios and the reverse speed ratio. For example,the first to second ratio interchange has a step of 1.47. It can also bereadily determined from the truth table of FIG. 3b that all of thesingle step forward ratio interchanges are of the single transitionvariety.

A powertrain 310, shown in FIG. 4a, includes the engine and torqueconverter 12, a planetary transmission 314, and the final drivemechanism 16. The planetary transmission 314 includes an input shaft 17continuously connected with the engine and torque converter 12, aplanetary gear arrangement 318, and output shaft 19 continuouslyconnected with the final drive mechanism 16. The planetary geararrangement 318 includes three planetary gear sets 320, 330 and 340.

The planetary gear set 320 includes a sun gear member 322, a ring gearmember 324, and a planet carrier assembly member 326. The planet carrierassembly member 326 includes a plurality of pinion gears 327 rotatablymounted on a carrier member 329 and disposed in meshing relationshipwith both the sun gear member 322 and the ring gear member 324.

The planetary gear set 330 includes a sun gear member 332, a ring gearmember 334, and a planet carrier assembly member 336. The planet carrierassembly member 336 includes a plurality of pinion gears 337 rotatablymounted on a carrier member 339 and disposed in meshing relationshipwith both the sun gear member 332 and the ring gear member 334.

The planetary gear set 340 includes a sun gear member 342, a ring gearmember 344, and a planet carrier assembly member 346. The planet carrierassembly member 346 includes a plurality of pinion gears 347 rotatablymounted on a carrier member 349 and disposed in meshing relationshipwith both the sun gear member 342 and the ring gear member 344.

The planetary gear arrangement 318 also includes six torque-transmittingmechanisms 350, 352, 354, 356, 358 and 359. The torque-transmittingmechanisms 350, 352, 354, 356 and 358 are rotating typetorque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanism 359 is a stationary-type torquetransmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member322, and the output shaft 19 is continuously connected with the ringgear member 334. The planet carrier assembly member 326 is continuouslyconnected with the sun gear member 332 through the interconnectingmember 370. The sun gear member 342 is continuously connected with thetransmission housing 360.

The ring gear member 324 is selectively connectable with the planetcarrier assembly member 326 through the clutch 350. The ring gear member324 is selectively connectable with the ring gear member 344 through theclutch 352. The sun gear member 322 is selectively connectable with theplanet carrier assembly member 336 through the clutch 354. The planetcarrier assembly member 336 is selectively connectable with the ringgear member 344 through the clutch 356. The ring gear member 334 isselectively connectable with the planet carrier assembly member 346through the clutch 358. The ring gear member 324 is selectivelyconnectable with the transmission housing 360 through the brake 359.

The truth tables given in FIGS. 4b, 5 b, 6 b, 7 b, 8 b, 9 b, 10 b, 11 b,12 b, 13 b, 14 b, 15 b, 16 b, 17 b, 18 b, 19 b and 20 b show theengagement sequences for the torque-transmitting mechanisms to provideat least seven forward speed ratios and at least one reverse ratio. Asshown and described above for the configuration in FIGS. 1a, 2 a and 3a, those skilled in the art will understand from the respective truthtables how the speed ratios are established through the planetary gearsets identified in the written description.

The truth table shown in FIG. 4b describes the engagement combinationand the engagement sequence necessary to provide the reverse drive ratioand seven forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 4b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given inFIG. 4b. The R1/S1 value is the tooth ratio for the planetary gear set320; the R2/S2 value is the tooth ratio for the planetary gear set 330;and the R3/S3 value is the tooth ratio for the planetary gear set 340.Also given in FIG. 4b is a chart describing the step ratios between theadjacent forward speed ratios and the reverse to first forward speedratio. For example, the first to second forward speed ratio step is1.61. It can be readily determined from the truth table of FIG. 4b thateach of the forward single step ratio interchanges is a singletransition shift.

Those skilled in the art will recognize that the numerical values of thereverse and seventh forward speed ratios are determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 320 and 330.The numerical values of the first, second and fifth forward speed ratioare determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 320, 330 and 340. The numerical value of the thirdforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 330 and 340. The numerical value ofthe fourth forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 340. The numerical value ofthe sixth forward speed ratio is one.

A powertrain 410, shown in FIG. 5a, includes the engine and torqueconverter 12, a planetary transmission 414 and the final drive mechanism16. The planetary transmission 414 includes a planetary gear arrangement418, input shaft 17 and output shaft 19. The planetary gear arrangement418 includes three simple planetary gear sets 420, 430 and 440.

The planetary gear set 420 includes a sun gear member 422, a ring gearmember 424, and a planet carrier assembly 426. The planet carrierassembly 426 includes a plurality of pinion gears 427 rotatably mountedon a carrier member 429 and disposed in meshing relationship with boththe sun gear member 422 and the ring gear member 424.

The planetary gear set 430 includes a sun gear member 432, a ring gearmember 434, and a planet carrier assembly member 436. The planet carrierassembly member 436 includes a plurality of pinion gears 437 rotatablymounted on a carrier member 439 and disposed in meshing relationshipwith both the sun gear member 432 and the ring gear member 434.

The planetary gear set 440 includes a sun gear member 442, a ring gearmember 444, and a planet carrier assembly member 446. The planet carrierassembly member 446 includes a plurality of pinion gears 447 rotatablymounted on a carrier member 449 and disposed in meshing relationshipwith both the sun gear member 442 and the ring gear member 444.

The planetary gear arrangement 418 also includes six torque-transmittingmechanisms 450, 452, 454, 456, 458 and 459. The torque-transmittingmechanisms 450, 452, 454, 456 and 458 are rotating typetorque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanisms 459 is a stationary-type torquetransmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member422, and the output shaft 19 is continuously connected with the ringgear member 434. The ring gear member 424 is continuously connected withthe planet carrier assembly member 436 through the interconnectingmember 470. The planet carrier assembly member 446 is continuouslyconnected with the transmission housing 460.

The ring gear member 424 is selectively connectable with the planetcarrier assembly member 426 through the clutch 450. The planet carrierassembly member 426 is selectively connectable with the ring gear member434 through the clutch 452. The sun gear member 422 is selectivelyconnectable with the sun gear member 442 through the clutch 454. The sungear member 432 is selectively connectable with the sun gear member 442through the clutch 456. The sun gear member 432 is selectivelyconnectable with the ring gear member 444 through the clutch 458. Theplanet carrier assembly member 436 is selectively connectable with thetransmission housing 460 through the brake 459.

The truth table shown in FIG. 5b describes the engagement combinationand sequence of the torque-transmitting mechanisms 450, 452, 454, 456,458 and 459 that are employed to provide the reverse drive ratio and theseven forward speed ratios. It should be noted that thetorque-transmitting mechanisms 454 and 459 are engaged through theneutral condition to simplify the forward/reverse interchange.

Also given in the truth table of FIG. 5b is a set of numerical valuesthat are attainable with the present invention utilizing the ringgear/sun gear tooth ratios shown. The R1/S1 value is the tooth ratio ofthe planetary gear set 420; the R2/S2 value is the tooth ratio of theplanetary gear set 430; and the R3/S3 value is the tooth ratio of theplanetary gear set 440. As can also be determined from the truth tableof FIG. 5b, the single step forward interchanges are single transitionshifts.

FIG. 5b also provides a chart of the ratio steps between adjacentforward ratios and between the reverse and first forward ratio. Forexample, the ratio step between the first and second forward ratios is1.82. Those skilled in the art will recognize that the numerical valueof the reverse and sixth forward speed ratios are determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 430. Thenumerical values of the first and seventh forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 430, 440. The numerical value of the second forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratioof the planetary gear set 420. The numerical value of the third forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 420, 430 and 440. The numerical value of thefourth forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 420 and 430. The numericalvalue of the fifth forward speed ratio is one.

A powertrain 510, shown in FIG. 6a, includes an engine and torqueconverter 12, a planetary gear transmission 514 and the final drivemechanism 16. The planetary transmission 514 includes the input shaft17, a planetary gear arrangement 518 and the output shaft 19. Theplanetary gear arrangement 518 includes three planetary gear sets 520,530 and 540.

The planetary gear set 520 includes a sun gear member 522, a ring gearmember 524, and a planet carrier assembly 526. The planet carrierassembly 526 includes a plurality of pinion gears 527 rotatably mountedon a carrier member 529 and disposed in meshing relationship with boththe sun gear member 522 and the ring gear member 524.

The planetary gear set 530 includes a sun gear member 532, a ring gearmember 534, and a planet carrier assembly member 536. The planet carrierassembly member 536 includes a plurality of pinion gears 537 rotatablymounted on a carrier member 539 and disposed in meshing relationshipwith both the sun gear member 532 and the ring gear member 534.

The planetary gear set 540 includes a sun gear member 542, a ring gearmember 544, and a planet carrier assembly member 546. The planet carrierassembly member 546 includes a plurality of pinion gears 547 rotatablymounted on a carrier member 549 and disposed in meshing relationshipwith both the sun gear member 542 and the ring gear member 544.

The planetary gear arrangement 518 also includes six torque-transmittingmechanisms 550, 552, 554, 556, 558 and 559. The torque-transmittingmechanisms 550, 552, 554, 556 and 558 are rotating typetorque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanism 559 is a stationary-type torquetransmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member522, and the output shaft 19 is continuously connected with the ringgear member 534. The ring gear member 524 is continuously connected withthe sun gear member 532 through the interconnecting member 570. The sungear member 542 is continuously connected with the transmission housing560.

The ring gear member 524 is selectively connectable with the planetcarrier assembly member 546 through the clutch 550. The planet carrierassembly member 526 is selectively connectable with the sun gear member522 through the clutch 552. The planet carrier assembly member 526 isselectively connectable with the ring gear member 544 through the clutch554. The sun gear member 522 is selectively connectable with the planetcarrier assembly member 536 through the clutch 556. The planet carrierassembly member 536 is selectively connectable with the planet carrierassembly member 546 through the clutch 558. The planet carrier assemblymember 526 is selectively connectable with the transmission housing 560through the brake 559.

The truth table shown in FIG. 6b describes the engagement sequence andcombination of the torque-transmitting mechanisms to provide the reversespeed ratio and seven forward speed ratios. It should be noted that thetorque-transmitting mechanisms 558 and 559 can remain engaged throughthe neutral condition, thereby simplifying the forward/reverseinterchange. It can also be determined from the truth table of FIG. 6bthat all of the single step forward ratio interchanges are of the singletransition variety. The chart of FIG. 6b describes the ratio stepsbetween adjacent forward speed ratios and the ratio step between thereverse and first forward speed ratio.

Those skilled in the art, upon reviewing the truth table and theschematic representation of FIG. 6a, can determine that the numericalvalue of the reverse speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 520. The numericalvalues of the first and seventh forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets520 and 530. The numerical value of the second forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 520 and 540. The numerical value of the thirdforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 530 and 540. The numerical values ofthe fourth and sixth forward speed ratios are determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 520, 530 and540. The numerical value of the fifth forward speed ratio is one.

The sample speed ratios given in the truth table are determinedutilizing the tooth ratio values also given in FIG. 6b. The R1/S1 valueis the tooth ratio of the planetary gear set 520; the R2/S2 value is thetooth ratio of the planetary gear set 530; and the R3/S3 value is thetooth ratio of the planetary gear set 540.

A powertrain 610, shown in FIG. 7a, has the engine and torque converter12, a planetary transmission 614 and the final drive mechanism 16. Theplanetary transmission 614 includes the input shaft 17, a planetary geararrangement 618 and the output shaft 19. The planetary gear arrangement618 includes three planetary gear sets 620, 630 and 640.

The planetary gear set 620 includes a sun gear member 622, a ring gearmember 624, and a planet carrier assembly 626. The planet carrierassembly 626 includes a plurality of pinion gears 627 rotatably mountedon a carrier member 629 and disposed in meshing relationship with boththe sun gear member 622 and the ring gear member 624.

The planetary gear set 630 includes a sun gear member 632, a ring gearmember 634, and a planet carrier assembly member 636. The planet carrierassembly member 636 includes a plurality of pinion gears 637 rotatablymounted on a carrier member 639 and disposed in meshing relationshipwith both the sun gear member 632 and the ring gear member 634.

The planetary gear set 640 includes a sun gear member 642, a ring gearmember 644, and a planet carrier assembly member 646. The planet carrierassembly member 646 includes a plurality of pinion gears 647 rotatablymounted on a carrier member 649 and disposed in meshing relationshipwith both the sun gear member 642 and the ring gear member 644.

The planetary gear arrangement 618 also includes six torque-transmittingmechanisms 650, 652, 654, 656, 658 and 659. The torque-transmittingmechanisms 650, 652, 654, 656 and 658 are rotating typetorque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanism 659 is a stationary-type torquetransmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member622, and the output shaft 19 is continuously connected with the ringgear member 634. The planet carrier assembly member 626 is continuouslyconnected with the sun gear member 632 through the interconnectingmember 670. The sun gear member 642 is continuously connected with thetransmission housing 660.

The sun gear member 632 is selectively connectable with the ring gearmember 644 through the clutch 650. The ring gear member 624 isselectively connectable with the ring gear member 644 through the clutch652. The ring gear member 624 is selectively connectable with the planetcarrier assembly member 646 through the clutch 654. The sun gear member622 is selectively connectable with the planet carrier assembly member636 through the clutch 656. The planet carrier assembly member 636 isselectively connectable with the planet carrier assembly member 646through the clutch 658. The ring gear member 624 is selectivelyconnectable with the transmission housing 660 through the brake 659.

The truth table shown in FIG. 7b describes the combination oftorque-transmitting mechanism engagements that will provide the reversedrive ratio and eight forward speed ratios, as well as the sequence ofthese engagements and interchanges. The torque-transmitting mechanisms658 and 659 can be engaged through the neutral condition, therebysimplifying the forward/reverse interchange.

The ratio values given are by way of example and are establishedutilizing the ring gear/sun gear tooth ratios given in FIG. 7b. Forexample, the R1/S1 value is the tooth ratio of the planetary gear set620; the R2/S2 value is the tooth ratio of the planetary gear set 630;and the R3/S3 value is the tooth ratio of the planetary gear set 640.The ratio steps between adjacent forward ratios and the reverse to firstratio are also given in FIG. 7b for 7-speed and 8-speed transmissions.

Those skilled in the art will, upon reviewing the truth table of FIG.7b, recognize that the numerical value of the reverse speed ratio isdetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 620, 630. The numerical values of the first, second,fifth and seventh forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 620, 630 and 640.The numerical values of the third and fourth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 630 and 640. The numerical value of the sixthforward speed ratio is one. The numerical value of the eighth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratioof the planetary gear set 630.

A powertrain 710, shown in FIG. 8a, has the conventional engine andtorque converter 12, a planetary transmission 714, and the conventionalfinal drive mechanism 16. The engine and torque converter 12 aredrivingly connected with the planetary transmission 714 through theinput shaft 17. The planetary transmission 714 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 714 includes a planetary gear arrangement 718that has a first planetary gear set 720, a second planetary gear set730, and a third planetary gear set 740.

The planetary gear set 720 includes a sun gear member 722, a ring gearmember 724, and a planet carrier assembly 726. The planet carrierassembly 726 includes a plurality of pinion gears 727 rotatably mountedon a carrier member 729 and disposed in meshing relationship with boththe sun gear member 722 and the ring gear member 724.

The planetary gear set 730 includes a sun gear member 732, a ring gearmember 734, and a planet carrier assembly member 736. The planet carrierassembly member 736 includes a plurality of pinion gears 737 rotatablymounted on a carrier member 739 and disposed in meshing relationshipwith both the sun gear member 732 and the ring gear member 734.

The planetary gear set 740 includes a sun gear member 742, a ring gearmember 744, and a planet carrier assembly member 746. The planet carrierassembly member 746 includes a plurality of pinion gears 747 rotatablymounted on a carrier member 749 and disposed in meshing relationshipwith both the sun gear member 742 and the ring gear member 744.

The planetary gear arrangement 718 also includes six torque-transmittingmechanisms 750, 752, 754, 756, 758 and 759. The torque-transmittingmechanisms 750, 752, 754 and 756 are rotating type torque-transmittingmechanisms, commonly termed clutches. The torque-transmitting mechanisms758 and 759 are stationary-type torque transmitting mechanisms, commonlytermed brakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member722, and the output shaft 19 is continuously connected with the ringgear member 734. The ring gear member 724 is continuously connected withthe planet carrier assembly member 736 through the interconnectingmember 770. The sun gear member 742 is continuously connected with thetransmission housing 760.

The planet carrier assembly member 736 is selectively connectable withthe ring gear member 744 through the clutch 750. The planet carrierassembly member 726 is selectively connectable with the ring gear member734 through the clutch 752. The sun gear member 722 is selectivelyconnectable with the planet carrier assembly member 746 through theclutch 754. The sun gear member 732 is selectively connectable with theplanet carrier assembly member 746 through the clutch 756. The planetcarrier assembly member 736 is selectively connectable with thetransmission housing 760 through the brake 758. The sun gear member 732is selectively connectable with the transmission housing 760 through thebrake 759.

The truth table of FIG. 8b defines the torque-transmitting mechanismengagement sequence utilized for each of the forward speed ratios andthe reverse speed ratio. Also given in the truth table is a set ofnumerical values that are attainable with the present inventionutilizing the ring gear/sun gear tooth ratios given in FIG. 8b. TheR1/S1 value is the tooth ratio of the planetary gear set 720; the R2/S2value is the tooth ratio of the planetary gear set 730; and the R3/S3value is the tooth ratio of the planetary gear set 740. As can also bedetermined from the truth table of FIG. 8b, the single and double stepforward interchanges are single transition shifts.

FIG. 8b also provides a chart of the ratio steps between adjacentforward ratios and between the reverse and first forward ratio. Forexample, the ratio step between the first and second forward ratios is1.94. Those skilled in the art will recognize that the numerical valueof the reverse speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 730. The numerical value ofthe first forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 720. The numerical value ofthe second forward speed ratio is determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 720 and 730. The numericalvalue of the third forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 720, 730 and 740.The numerical value of the fourth forward speed ratio is one. Thenumerical value of the fifth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 720 and740. The numerical values of the sixth and seventh forward speed ratiosare determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 730 and 740.

A powertrain 810, shown in FIG. 9a, has the conventional engine andtorque converter 12, a planetary transmission 814, and the final drivemechanism 16. The engine and torque converter 12 are drivingly connectedwith the planetary transmission 814 through the input shaft 17. Theplanetary transmission 814 is drivingly connected with the final drivemechanism 16 through the output shaft 19. The planetary transmission 814includes a planetary gear arrangement 818 that has a first planetarygear set 820, a second planetary gear set 830, and a third planetarygear set 840.

The planetary gear set 820 includes a sun gear member 822, a ring gearmember 824, and a planet carrier assembly 826. The planet carrierassembly 826 includes a plurality of pinion gears 827 rotatably mountedon a carrier member 829 and disposed in meshing relationship with boththe sun gear member 822 and the ring gear member 824.

The planetary gear set 830 includes a sun gear member 832, a ring gearmember 834, and a planet carrier assembly member 836. The planet carrierassembly member 836 includes a plurality of pinion gears 837 rotatablymounted on a carrier member 839 and disposed in meshing relationshipwith both the sun gear member 832 and the ring gear member 834.

The planetary gear set 840 includes a sun gear member 842, a ring gearmember 844, and a planet carrier assembly member 846. The planet carrierassembly member 846 includes a plurality of pinion gears 847 rotatablymounted on a carrier member 849 and disposed in meshing relationshipwith both the sun gear member 842 and the ring gear member 844.

The planetary gear arrangement 818 also includes six torque-transmittingmechanisms 850, 852, 854, 856, 858 and 859. The torque-transmittingmechanisms 850, 852, 854 and 856 are rotating type torque-transmittingmechanisms, commonly termed clutches. The torque-transmitting mechanisms858 and 859 are stationary-type torque transmitting mechanisms, commonlytermed brakes or reaction clutches.

The input shaft 17 is continuously connected with the sun gear member822, and the output shaft 19 is continuously connected with ring gearmember 834. The ring gear member 824 is continuously connected with thesun gear member 832 through the interconnecting member 870. The sun gearmember 842 is continuously connected with the transmission housing 860.

The sun gear member 832 is selectively connectable with the planetcarrier assembly member 846 through the clutch 850. The planet carrierassembly member 826 is selectively connectable with the ring gear member844 through the clutch 852. The sun gear member 822 is selectivelyconnectable with the planet carrier assembly member 836 through theclutch 854. The planet carrier assembly member 836 is selectivelyconnectable with the planet carrier assembly member 846 through theclutch 856. The planet carrier assembly member 826 is selectivelyconnectable with the transmission housing 860 through the brake 858. Thering gear member 844 is selectively connectable with the transmissionhousing 860 through the brake 859.

The truth table shown in FIG. 9b defines the torque-transmittingmechanism engagement sequence that provides the reverse speed ratio andseven forward speed ratios shown in the truth table and available withthe planetary gear arrangement 818. The truth table indicates that thetorque-transmitting mechanism 856 can remain engaged through the neutralcondition, thereby simplifying the forward/reverse interchange. A sampleof numerical values for the individual ratios is also given in the truthtable of FIG. 9b. These numerical values have been calculated using thering gear/sun gear tooth ratios also given by way of example in FIG. 9b.The R1/S1 value is the tooth ratio of the planetary gear set 820; theR2/S2 value is the tooth ratio of the planetary gear set 830; and theR3/S3 value is the tooth ratio of the planetary gear set 840. It can bereadily recognized from the truth table that all of the single stepforward interchanges are single transition ratio interchanges, exceptthe reverse to first step. FIG. 9b also describes the ratio stepsbetween adjacent forward ratios and between the reverse and firstforward ratio. For example, the ratio step between the first and secondforward ratios is 1.94.

Those skilled in the art of planetary transmissions will recognize thatthe numerical value of the reverse speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 820. Thenumerical values of the first and seventh forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 820 and 830. The numerical value of the secondforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 820 and 840. The numerical values ofthe third and fifth forward speed ratios are determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 820, 830 and840. The numerical value of the fourth forward speed ratio is one. Thenumerical value of the sixth forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 830.

The powertrain 910, shown in FIG. 10a, includes the conventional engineand torque converter 12, a planetary transmission 914, and theconventional final drive mechanism 16. The engine and torque converter12 are drivingly connected with the planetary transmission 914 throughthe input shaft 17. The planetary transmission 914 is drivinglyconnected with the final drive mechanism 16 through the output shaft 19.The planetary transmission 914 includes a planetary gear arrangement 918that has a first planetary gear set 920, a second planetary gear set930, and a third planetary gear set 940.

The planetary gear set 920 includes a sun gear member 922, a ring gearmember 924, and a planet carrier assembly 926. The planet carrierassembly 926 includes a plurality of pinion gears 927 that are rotatablymounted on a carrier member 929 and disposed in meshing relationshipwith the sun gear member 922 and the ring gear member 924, respectively.

The planetary gear set 930 includes a sun gear member 932, a ring gearmember 934, and a planet carrier assembly member 936. The planet carrierassembly member 936 includes a plurality of pinion gears 937 rotatablymounted on a carrier member 939 and disposed in meshing relationshipwith both the sun gear member 932 and the ring gear member 934.

The planetary gear set 940 includes a sun gear member 942, a ring gearmember 944, and a planet carrier assembly member 946. The planet carrierassembly member 946 includes a plurality of pinion gears 947 rotatablymounted on a carrier member 949 and disposed in meshing relationshipwith both the sun gear member 942 and the ring gear member 944.

The planetary gear arrangement 918 also includes six torque-transmittingmechanisms 950, 952, 954, 956, 958 and 959. The torque-transmittingmechanisms 950, 952, 954, 956 and 958 are rotating typetorque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanism 959 is a stationary-type torquetransmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member922, and the output shaft 19 is continuously connected with the ringgear member 934. The planet carrier assembly member 926 is continuouslyconnected with the planet carrier assembly member 936 through theinterconnecting member 970. The sun gear member 942 is continuouslyconnected with the transmission housing 960.

The planet carrier assembly member 936 is selectively connectable withthe sun gear member 932 through the clutch 950. The ring gear member 924is selectively connectable with the sun gear member 932 through theclutch 952. The ring gear member 924 is selectively connectable with thering gear member 944 through the clutch 954. The sun gear member 922 isselectively connectable with the planet carrier assembly member 946through the clutch 956. The sun gear member 932 is selectivelyconnectable with the planet carrier assembly member 946 through theclutch 958. The planet carrier assembly member 936 is selectivelyconnectable with the transmission housing 960 through the brake 959.

The truth table of FIG. 10b describes the torque-transmitting mechanismengagement sequence utilized to provide the reverse speed ratio andseven forward speed ratios. The truth table also provides a set ofexamples for the ratios for each of the reverse and forward speedratios. These numerical values have been determined utilizing the ringgear/sun gear tooth ratios given in FIG. 10b. The R1/S1 value is thetooth ratio of the planetary gear set 920; the R2/S2 value is the toothratio of the planetary gear set 930; and the R3/S3 value is the toothratio of the planetary gear set 940.

Those skilled in the art, upon reviewing the engagement combinations,will recognize that the numerical value of the reverse speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 930. The numerical values of the first, fifth and seventhforward speed ratios are determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 920, 930 and 940. The numericalvalues of the second and third forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets920 and 930. The numerical value of the fourth forward speed ratio is 1.The numerical value of the sixth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets920 and 940.

A powertrain 1010, shown in FIG. 11a, includes the conventional engineand torque converter 12, a planetary transmission 1014, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1014 through theinput shaft 17. The planetary transmission 1014 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1014 includes a planetary gear arrangement 1018that has a first planetary gear set 1020, a second planetary gear set1030, and a third planetary gear set 1040.

The planetary gear set 1020 includes a sun gear member 1022, a ring gearmember 1024, and a planet carrier assembly 1026. The planet carrierassembly 1026 includes a plurality of pinion gears 1027 rotatablymounted on a carrier member 1029 and disposed in meshing relationshipwith both the sun gear member 1022 and the ring gear member 1024.

The planetary gear set 1030 includes a sun gear member 1032, a ring gearmember 1034, and a planet carrier assembly member 1036. The planetcarrier assembly member 1036 includes a plurality of pinion gears 1037rotatably mounted on a carrier member 1039 and disposed in meshingrelationship with both the sun gear member 1032 and the ring gear member1034.

The planetary gear set 1040 includes a sun gear member 1042, a ring gearmember 1044, and a planet carrier assembly member 1046. The planetcarrier assembly member 1046 includes a plurality of pinion gears 1047rotatably mounted on a carrier member 1049 and disposed in meshingrelationship with both the sun gear member 1042 and the ring gear member1044.

The planetary gear arrangement 1018 also includes sixtorque-transmitting mechanisms 1050, 1052, 1054, 1056, 1058 and 1059.The torque-transmitting mechanisms 1050, 1052, 1054 and 1056 arerotating type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 1058 and 1059 are stationary-typetorque transmitting mechanisms, commonly termed brakes or reactionclutches.

The input shaft 17 is continuously connected with the sun gear member1022, and the output shaft 19 is continuously connected with the ringgear member 1034. The planet carrier assembly member 1026 iscontinuously connected with the planet carrier assembly member 1036through the interconnecting member 1070. The sun gear member 1042 iscontinuously connected with the transmission housing 1060.

The ring gear member 1024 is selectively connectable with the sun gearmember 1032 through the clutch 1050. The ring gear member 1024 isselectively connectable with the ring gear member 1044 through theclutch 1052. The sun gear member 1022 is selectively connectable withthe planet carrier assembly member 1046 through the clutch 1054. The sungear member 1032 is selectively connectable with the planet carrierassembly member 1046 through the clutch 1056. The planet carrierassembly member 1036 is selectively connectable with the transmissionhousing 1060 through the brake 1058. The sun gear member 1032 isselectively connectable with the transmission housing 1060 through thebrake 1059.

The truth table shown in FIG. 11b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand the seven forward speed ratios. A sample of the numerical values forthe ratios is also provided in the truth table of FIG. 11b. These valuesare determined utilizing the ring gear/sun gear tooth ratios also givenin FIG. 11b. The R1/S1 value is the tooth ratio for the planetary gearset 1020; the R2/S2 value is the tooth ratio for the planetary gear set1030; and the R3/S3 value is the tooth ratio for the planetary gear set1040. Also given in FIG. 11b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1030. The numerical values of the first,fifth, sixth and seventh forward speed ratios are determined utilizingthe ring gear/sun gear tooth ratios of the planetary gear sets 1020,1030 and 1040. The numerical values of the second and third forwardspeed ratios are determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1020 and 1030. The numerical value ofthe fourth forward speed ratio is one.

A powertrain 1110, shown in FIG. 12a, has a conventional engine andtorque converter 12, a planetary transmission 1114, and the conventionalfinal drive mechanism 16. The planetary transmission 1114 includes aplanetary gear arrangement 1118 which is connected with the engine andtorque converter 12 through the input shaft 17 and with the final drivemechanism 16 through the output shaft 19. The planetary gear arrangement1118 includes three planetary gear sets 1120, 1130 and 1140.

The planetary gear set 1120 includes a sun gear member 1122, a ring gearmember 1124, and a planet carrier assembly 1126. The planet carrierassembly 1126 includes a plurality of pinion gears 1127 rotatablymounted on a carrier member 1129 and disposed in meshing relationshipwith both the sun gear member 1122 and the ring gear member 1124.

The planetary gear set 1130 includes a sun gear member 1132, a ring gearmember 1134, and a planet carrier assembly member 1136. The planetcarrier assembly member 1136 includes a plurality of intermeshing piniongears 1137 that are rotatably mounted on a carrier member 1139 anddisposed in meshing relationship with both the sun gear member 1132 andthe ring gear member 1134.

The planetary gear set 1140 includes a sun gear member 1142, a ring gearmember 1144, and a planet carrier assembly member 1146. The planetcarrier assembly member 1146 includes a plurality of pinion gears 1147and 1148 rotatably mounted on a carrier member 1149 and disposed inmeshing relationship with both the sun gear member 1142 and the ringgear member 1144.

The planetary gear arrangement 1118 also includes sixtorque-transmitting mechanisms 1150, 1152, 1154, 1156, 1158 and 1159.The torque-transmitting mechanisms 1150, 1152, 1154, 1156 and 1158 arerotating type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanism 1159 is a stationary-type torquetransmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member1142, and the output shaft 19 is continuously connected with the planetcarrier assembly member 1126. The planet carrier assembly member 1126 iscontinuously connected with the ring gear member 1134 through theinterconnecting member 1170. The planet carrier assembly member 1146 iscontinuously connected with the transmission housing 1160.

The sun gear member 1122 is selectively connectable with the planetcarrier assembly member 1136 through the clutch 1150. The ring gearmember 1124 is selectively connectable with the planet carrier assemblymember 1136 through the clutch 1152. The ring gear member 1124 isselectively connectable with the sun gear member 1142 through the clutch1154. The sun gear member 1132 is selectively connectable with the ringgear member 1144 through the clutch 1156. The planet carrier assemblymember 1136 is selectively connectable with the ring gear member 1144through the clutch 1158. The sun gear member 1122 is selectivelyconnectable with the transmission housing 1160 through the brake 1159.

The truth table shown in FIG. 12b describes the engagement sequence andengagement combinations utilized with the present family member toprovide the reverse drive ratio and eight forward speed ratios. Thetruth table of FIG. 12b also provides a set of example numbers that canbe established in the planetary gear arrangement 1118 utilizing the ringgear/sun gear tooth ratios. The R1/S1 value is the ring gear/sun geartooth ratio of the planetary gear set 1120; the R2/S2 value is the ringgear/sun gear tooth ratio of the planetary gear set 1130; and the R3/S3value is the ring gear/sun gear tooth ratio of the planetary gear set1140.

The chart of FIG. 12b describes the ratio steps between adjacent forwardspeed ratios for seven-speed and eight-speed transmissions. These stepratios are established utilizing the example speed ratios given in thetruth table.

Those skilled in the art will recognize that the numerical values of thereverse and eighth forward speed ratios are determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 1130, 1140.The numerical values of the first and sixth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1120, 1130 and 1140. The numerical values of thesecond and fifth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1120 and 1140. Thenumerical value of the third forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 1140. Thenumerical value of the fourth forward speed ratio is determinedutilizing the ring gear/sun gear tooth ratio of the planetary gear set1120. The numerical value of the seventh forward speed ratio is one.

A powertrain 1210, shown in FIG. 13a, includes the conventional engineand torque converter 12, a planetary transmission 1214, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1214 through theinput shaft 17. The planetary transmission 1214 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1214 includes a planetary gear arrangement 1218that has a first planetary gear set 1220, a second planetary gear set1230, and a third planetary gear set 1240.

The planetary gear set 1220 includes a sun gear member 1222, a ring gearmember 1224, and a planet carrier assembly 1226. The planet carrierassembly 1226 includes a plurality of pinion gears 1227 rotatablymounted on a carrier member 1229 and disposed in meshing relationshipwith both the sun gear member 1222 and the ring gear member 1224.

The planetary gear set 1230 includes a sun gear member 1232, a ring gearmember 1234, and a planet carrier assembly member 1236. The planetcarrier assembly member 1236 includes a plurality of pinion gears 1237rotatably mounted on a carrier member 1239 and disposed in meshingrelationship with both the sun gear member 1232 and the ring gear member1234.

The planetary gear set 1240 includes a sun gear member 1242, a ring gearmember 1244, and a planet carrier assembly member 1246. The planetcarrier assembly member 1246 includes a plurality of pinion gears 1247rotatably mounted on a carrier member 1249 and disposed in meshingrelationship with both the sun gear member 1242 and the ring gear member1244.

The planetary gear arrangement 1218 also includes six torquetransmitting mechanisms 1250, 1252, 1254, 1256, 1258 and 1259. Thetorque-transmitting mechanisms 1250, 1252, 1254, 1256 and 1258 arerotating type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanism 1259 is a stationary-type torquetransmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member1222, and the output shaft 19 is continuously connected with the ringgear member 1234. The planet carrier assembly member 1226 iscontinuously connected with the sun gear member 1232 through theinterconnecting member 1270. The sun gear member 1242 is continuouslyconnected with the transmission housing 1260.

The ring gear member 1224 is selectively connectable with the planetcarrier assembly member 1226 through the clutch 1250. The planet carrierassembly member 1226 is selectively connectable with the ring gearmember 1244 through the clutch 1252. The ring gear member 1224 isselectively connectable with the planet carrier assembly member 1246through the clutch 1254. The sun gear member 1222 is selectivelyconnectable with the planet carrier assembly member 1236 through theclutch 1256. The planet carrier assembly member 1236 is selectivelyconnectable with the planet carrier assembly member 1246 through theclutch 1258. The ring gear member 1224 is selectively connectable withthe transmission housing 1260 through the brake 1259.

The truth table shown in FIG. 13b describes the engagement combinationsand the engagement sequence necessary to provide a reverse speed ratioand seven forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 13b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given inFIG. 13b. The R1/S1 value is the tooth ratio for the planetary gear set1220; the R2/S2 value is the tooth ratio for the planetary gear set1230; and the R3/S3 value is the tooth ratio for the planetary gear set1240. Also given in FIG. 13b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical values of thereverse and seventh forward speed ratios are determined utilizing thering gear/sun gear tooth ratios of the planetary gear sets 1220 and1230. The numerical values of the first, second and sixth forward speedratios are determined utilizing the ring gear/sun gear tooth ratios ofthe planetary gear sets 1220, 1230 and 1240. The numerical values of thethird and fourth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1230 and 1240. Thenumerical value of the fifth forward speed ratio is one.

A powertrain 1310, shown in FIG. 14a, includes the conventional engineand torque converter 12, a planetary transmission 1314, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1314 through theinput shaft 17. The planetary transmission 1314 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1314 includes a planetary gear arrangement 1318that has a first planetary gear set 1320, a second planetary gear set1330, and a third planetary gear set 1340.

The planetary gear set 1320 includes a sun gear member 1322, a ring gearmember 1324, and a planet carrier assembly 1326. The planet carrierassembly 1326 includes a plurality of pinion gears 1327 rotatablymounted on a carrier member 1329 and disposed in meshing relationshipwith both the sun gear member 1322 and the ring gear member 1324.

The planetary gear set 1330 includes a sun gear member 1332, a ring gearmember 1334, and a planet carrier assembly member 1336. The planetcarrier assembly member 1336 includes a plurality of pinion gears 1337rotatably mounted on a carrier member 1339 and disposed in meshingrelationship with both the sun gear member 1332 and the ring gear member1334.

The planetary gear set 1340 includes a sun gear member 1342, a ring gearmember 1344, and a planet carrier assembly member 1346. The planetcarrier assembly member 1346 includes a plurality of pinion gears 1347rotatably mounted on a carrier member 1349 and disposed in meshingrelationship with both the sun gear member 1342 and the ring gear member1344.

The planetary gear arrangement 1318 also includes six torquetransmitting mechanisms 1350, 1352, 1354, 1356, 1358 and 1359. Thetorque-transmitting mechanisms 1350, 1352, 1354 and 1356 are rotatingtype torque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanisms 1358 and 1359 are stationary-type torquetransmitting mechanisms, commonly termed brakes or reaction clutches.

The input shaft 17 is continuously connected with the ring gear member1344, and the output shaft 19 is continuously connected with the ringgear member 1334. The planet carrier assembly member 1326 iscontinuously connected with the planet carrier assembly member 1336through the interconnecting member 1370. The sun gear member 1342 iscontinuously connected with the transmission housing 1360.

The planet carrier assembly member 1336 is selectively connectable withthe ring gear member 1344 through the clutch 1350. The ring gear member1324 is selectively connectable with the sun gear member 1332 throughthe clutch 1352. The ring gear member 1324 is selectively connectablewith the planet carrier assembly member 1346 through the clutch 1354.The sun gear member 1332 is selectively connectable with the ring gearmember 1344 through the clutch 1356. The ring gear member 1324 isselectively connectable with the transmission housing 1360 through thebrake 1358. The sun gear member 1322 is selectively connectable with thetransmission housing 1360 through the brake 1359.

The truth table shown in FIG. 14b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand seven forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 14b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given inFIG. 14b. The R1/S1 value is the tooth ratio for the planetary gear set1320; the R2/S2 value is the tooth ratio for the planetary gear set1330; and the R3/S3 value is the tooth ratio for the planetary gear set1340. Also given in FIG. 14b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1330. The numerical values of the firstand second forward speed ratio are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1320, 1330 and1340. The numerical values of the third and fourth forward speed ratioare determined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1320 and 1330. The numerical value of the fifthforward speed ratio is one. The numerical value of the sixth forwardspeed ratio is determined utilizing the ring gear/sun gear tooth ratiosof the planetary gear sets 1330 and 1340. The numerical value of theseventh forward speed ratio is determined utilizing the ring gear/sungear tooth ratio of the planetary gear set 1330.

A powertrain 1410, shown in FIG. 15a, includes the conventional engineand torque converter 12, a planetary transmission 1414, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1414 through theinput shaft 17. The planetary transmission 1414 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1414 includes a planetary gear arrangement 1418that has a first planetary gear set 1420, a second planetary gear set1430, and a third planetary gear set 1440.

The planetary gear set 1420 includes a sun gear member 1422, a ring gearmember 1424, and a planet carrier assembly 1426. The planet carrierassembly 1426 includes a plurality of pinion gears 1427 rotatablymounted on a carrier member 1429 and disposed in meshing relationshipwith both the sun gear member 1422 and the ring gear member 1424.

The planetary gear set 1430 includes a sun gear member 1432, a ring gearmember 1434, and a planet carrier assembly member 1436. The planetcarrier assembly member 1436 includes a plurality of pinion gears 1437rotatably mounted on a carrier member 1439 and disposed in meshingrelationship with both the sun gear member 1432 and the ring gear member1434.

The planetary gear set 1440 includes a sun gear member 1442, a ring gearmember 1444, and a planet carrier assembly member 1446. The planetcarrier assembly member 1446 includes a plurality of pinion gears 1447rotatably mounted on a carrier member 1449 and disposed in meshingrelationship with both the sun gear member 1442 and the ring gear member1444.

The planetary gear arrangement 1418 also includes six torquetransmitting mechanisms 1450, 1452, 1454, 1456, 1458 and 1459. Thetorque-transmitting mechanisms 1450, 1452, 1454 and 1456 are rotatingtype torque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanisms 1458 and 1459 are stationary-type torquetransmitting mechanisms, commonly termed brakes or reaction clutches

The input shaft 17 is continuously connected with the sun gear member1442, and the output shaft 19 is continuously connected with the ringgear member 1434. The ring gear member 1424 is continuously connectedwith the sun gear member 1432 through the interconnecting member 1470.The ring gear member 1444 is continuously connected with thetransmission housing 1460.

The ring gear member 1424 is selectively connectable with the sun gearmember 1442 through the clutch 1450. The planet carrier assembly member1426 is selectively connectable with the planet carrier assembly member1436 through the clutch 1452. The planet carrier assembly member 1426 isselectively connectable with the planet carrier assembly member 1446through the clutch 1454. The planet carrier assembly member 1436 isselectively connectable with the sun gear member 1442 through the clutch1456. The planet carrier assembly member 1426 is selectively connectablewith the transmission housing 1460 through the brake 1458. The sun gearmember 1422 is selectively connectable with the transmission housing1460 through the brake 1459.

The truth table shown in FIG. 15b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand seven forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 15b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given inFIG. 15b. The R1/S1 value is the tooth ratio for the planetary gear set1420; the R2/S2 value is the tooth ratio for the planetary gear set1430; and the R3/S3 value is the tooth ratio for the planetary gear set1440. Also given in FIG. 15b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical values of thefirst and seventh forward speed ratios are determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 1430. The numericalvalue of the first forward speed ratio is determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1430 and 1440. Thenumerical value of the second and sixth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1420, 1430 and 1440. The numerical values of thethird and fourth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1420 and 1430. Thenumerical value of the fifth forward speed ratio is one.

A powertrain 1510, shown in FIG. 16a, includes the conventional engineand torque converter 12, a planetary transmission 1514, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1514 through theinput shaft 17. The planetary transmission 1514 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1514 includes a planetary gear arrangement 1518that has a first planetary gear set 1520, a second planetary gear set1530, and a third planetary gear set 1540.

The planetary gear set 1520 includes a sun gear member 1522, a ring gearmember 1524, and a planet carrier assembly 1526. The planet carrierassembly 1526 includes a plurality of pinion gears 1527 rotatablymounted on a carrier member 1529 and disposed in meshing relationshipwith both the sun gear member 1522 and the ring gear member 1524.

The planetary gear set 1530 includes a sun gear member 1532, a ring gearmember 1534, and a planet carrier assembly member 1536. The planetcarrier assembly member 1536 includes a plurality of pinion gears 1537rotatably mounted on a carrier member 1539 and disposed in meshingrelationship with both the sun gear member 1532 and the ring gear member1534.

The planetary gear set 1540 includes a sun gear member 1542, a ring gearmember 1544, and a planet carrier assembly member 1546. The planetcarrier assembly member 1546 includes a plurality of pinion gears 1547rotatably mounted on a carrier member 1549 and disposed in meshingrelationship with both the sun gear member 1542 and the ring gear member1544.

The planetary gear arrangement 1518 also includes six torquetransmitting mechanisms 1550, 1552, 1554, 1556, 1558 and 1559. Thetorque-transmitting mechanisms 1550, 1552, 1554 and 1556 are rotatingtype torque-transmitting mechanisms, commonly termed clutches. Thetorque-transmitting mechanisms 1558 and 1559 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

The input shaft 17 is continuously connected with the sun gear member1522, and the output shaft 19 is continuously connected with the ringgear member 1534. The ring gear member 1524 is continuously connectedwith the planet carrier assembly member 1536 through the interconnectingmember 1570. The sun gear member 1542 is continuously connected withtransmission housing 1560.

The planet carrier assembly member 1526 is selectively connectable withthe ring gear member 1534 through the clutch 1550. The planet carrierassembly member 1526 is selectively connectable with the ring gearmember 1544 through the clutch 1552. The sun gear member 1522 isselectively connectable with the planet carrier assembly member 1546through the clutch 1554. The sun gear member 1532 is selectivelyconnectable with the planet carrier assembly member 1546 through theclutch 1556. The planet carrier assembly member 1536 is selectivelyconnectable with the transmission housing 1560 through the brake 1558.The sun gear member 1532 is selectively connectable with thetransmission housing 1560 through the brake 1559.

The truth table shown in FIG. 16b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand the seven forward speed ratios. A sample of the numerical values forthe ratios is also provided in the truth table of FIG. 16b. These valuesare determined utilizing the ring gear/sun gear tooth ratios also givenin FIG. 16b. The R1/S1 value is the tooth ratio for the planetary gearset 1520; the R2/S2 value is the tooth ratio for the planetary gear set1530; and the R3/S3 value is the tooth ratio for the planetary gear set1540. Also given in FIG. 16b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1530. The numerical value of the firstforward speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1520. The numerical value of the secondforward speed ratio is determined utilizing the ring gear/sun gear toothratios of the planetary gear sets 1520 and 1530. The numerical values ofthe third, sixth and seventh forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1520, 1530 and 1540. The numerical value of the fourth forward speedratio is one. The numerical value of the fifth forward speed ratio isdetermined utilizing the ring gear/sun gear tooth ratio of the planetarygear set 1540.

A powertrain 1610, shown in FIG. 17a, includes the conventional engineand torque converter 12, a planetary transmission 1614, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1614 through theinput shaft 17. The planetary transmission 1614 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1614 includes a planetary gear arrangement 1618that has a first planetary gear set 1620, a second planetary gear set1630, and a third planetary gear set 1640.

The planetary gear set 1620 includes a sun gear member 1622, a ring gearmember 1624, and a planet carrier assembly 1626. The planet carrierassembly 1626 includes a plurality of pinion gears 1627 rotatablymounted on a carrier member 1629 and disposed in meshing relationshipwith both the sun gear member 1622 and the ring gear member 1624.

The planetary gear set 1630 includes a sun gear member 1632, a ring gearmember 1634, and a planet carrier assembly member 1636. The planetcarrier assembly member 1636 includes a plurality of pinion gears 1637rotatably mounted on a carrier member 1639 and disposed in meshingrelationship with both the sun gear member 1632 and the ring gear member1634.

The planetary gear set 1640 includes a sun gear member 1642, a ring gearmember 1644, and a planet carrier assembly member 1646. The planetcarrier assembly member 1646 includes a plurality of pinion gears 1647rotatably mounted on a carrier member 1649 and disposed in meshingrelationship with both the sun gear member 1642 and the ring gear member1644.

The planetary gear arrangement 1618 also includes six torquetransmitting mechanisms 1650, 1652, 1654, 1656, 1658 and 1659. Thetorque-transmitting mechanisms 1650, 1652, 1654 and 1656 are of therotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanisms 1658 and 1659 are stationary-typetorque-transmitting mechanisms, commonly termed brakes or reactionclutches.

The input shaft 17 is continuously connected with the sun gear member1622, and the output shaft 19 is continuously connected with the ringgear member 1634. The planet carrier assembly member 1626 iscontinuously connected with the planet carrier assembly member 1636through the interconnecting member 1670. The sun gear member 1642 iscontinuously connected with the transmission housing 1660.

The planet carrier assembly member 1626 is selectively connectable withthe ring gear member 1644 through the clutch 1650. The ring gear member1624 is selectively connectable with the sun gear member 1632 throughthe clutch 1652. The sun gear member 1622 is selectively connectablewith the planet carrier assembly member 1646 through the clutch 1654.The sun gear member 1632 is selectively connectable with the planetcarrier assembly member 1646 through the clutch 1656. The planet carrierassembly member 1636 is continuously connected with the transmissionhousing 1660 through the brake 1658. The sun gear member 1632 isselectively connectable with the transmission housing 1660 through thebrake 1659.

The truth table shown in FIG. 17b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand the seven forward speed ratios. A sample of the numerical values forthe ratios is also provided in the truth table of FIG. 17b. These valuesare determined utilizing the ring gear/sun gear tooth ratios also givenin FIG. 17b. The R1/S1 value is the tooth ratio for the planetary gearset 1620; the R2/S2 value is the tooth ratio for the planetary gear set1630; and the R3/S3 value is the tooth ratio for the planetary gear set1640. Also given in FIG. 17b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical value of thereverse speed ratio is determined utilizing the ring gear/sun gear toothratio of the planetary gear set 1630. The numerical values of the firstand second forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1620 and 1630. Thenumerical values of the third and fifth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1620, 1630 and 1640. The numerical value of thefourth forward speed ratio is one. The numerical values of the sixth andseventh forward speed ratios are determined utilizing the ring gear/sungear tooth ratios of the planetary gear sets 1630 and 1640.

A powertrain 1710, shown in FIG. 18a, includes the conventional engineand torque converter 12, a planetary transmission 1714, and theconventional final drive mechanism 16. The engine and torque converterare drivingly connected with the planetary transmission 1714 through theinput shaft 17. The planetary transmission 1714 is drivingly connectedwith the final drive mechanism 16 through the output shaft 19. Theplanetary transmission 1714 includes a planetary gear arrangement 1718that has a first planetary gear set 1720, a second planetary gear set1730, and a third planetary gear set 1740.

The planetary gear set 1720 includes a sun gear member 1722, a ring gearmember 1724, and a planet carrier assembly 1726. The planet carrierassembly 1726 includes a plurality of pinion gears 1727 rotatablymounted on a carrier member 1729 and disposed in meshing relationshipwith both the sun gear member 1722 and the ring gear member 1724.

The planetary gear set 1730 includes a sun gear member 1732, a ring gearmember 1734, and a planet carrier assembly member 1736. The planetcarrier assembly member 1736 includes a plurality of pinion gears 1737rotatably mounted on a carrier member 1739 and disposed in meshingrelationship with both the sun gear member 1732 and the ring gear member1734.

The planetary gear set 1740 includes a sun gear member 1742, a ring gearmember 1744, and a planet carrier assembly member 1746. The planetcarrier assembly member 1746 includes a plurality of pinion gears 1747rotatably mounted on a carrier member 1749 and disposed in meshingrelationship with both the sun gear member 1742 and the ring gear member1744.

The planetary gear arrangement 1718 also includes six torquetransmitting mechanisms 1750, 1752, 1754, 1756, 1758 and 1759. Thetorque-transmitting mechanisms 1750, 1752, 1754, 1756 and 1758 arerotating-type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanism 1759 is a stationary-typetorque-transmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member1742, and the output shaft 19 is continuously connected with the ringgear member 1734. The sun gear member 1722 is continuously connectedwith the sun gear member 1732 through the interconnecting member 1770.The ring gear member 1744 is continuously connected with thetransmission housing 1760.

The sun gear member 1732 is selectively connectable with the planetcarrier assembly member 1746 through the clutch 1750. The ring gearmember 1724 is selectively connectable with the sun gear member 1742through the clutch 1752. The planet carrier assembly member 1726 isselectively connectable with the ring gear member 1734 through theclutch 1754. The planet carrier assembly member 1726 is selectivelyconnectable with the planet carrier assembly member 1736 through theclutch 1756. The planet carrier assembly member 1736 is selectivelyconnectable with the planet carrier assembly member 1746 through theclutch 1758. The ring gear member 1724 is selectively connectable withthe transmission housing 1760 through the brake 1759.

The truth table shown in FIG. 18b describes the engagement combinationsand the engagement sequence necessary to provide the reverse drive ratioand eight forward speed ratios. A sample of the numerical values for theratios is also provided in the truth table of FIG. 18b. These values aredetermined utilizing the ring gear/sun gear tooth ratios also given inFIG. 18b. The R1/S1 value is the tooth ratio for the planetary gear set1720; the R2/S2 value is the tooth ratio for the planetary gear set1730; and the R3/S3 value is the tooth ratio for the planetary gear set1740. Also given in FIG. 18b is a chart describing the step ratiosbetween the adjacent forward speed ratios and the reverse to firstforward speed ratio.

Those skilled in the art will recognize that the numerical values of thereverse, second, fourth, seventh and eighth forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1720, 1730 and 1740. The numerical values of thefirst and fifth forward speed ratios are determined utilizing the ringgear/sun gear tooth ratios of the planetary gear sets 1720 and 1740. Thenumerical value of the third forward speed ratio is determined utilizingthe ring gear/sun gear tooth ratio of the planetary gear set 1740. Thenumerical value of the sixth forward speed ratio is one.

A powertrain 1810, shown in FIG. 19a, has the conventional engine andtorque converter 12, a planetary transmission 1814, and the final drivemechanism 16. The engine and torque converter 12 are drivingly connectedwith the planetary transmission 1814 through the input shaft 17. Theplanetary transmission 1814 is drivingly connected with the final drivemechanism 16 through the output shaft 19. The planetary transmission1814 includes a planetary gear arrangement 1818 that has a firstplanetary gear set 1820, a second planetary gear set 1830, and a thirdplanetary gear set 1840.

The planetary gear set 1820 includes a sun gear member 1822, a ring gearmember 1824, and a planet carrier assembly 1826. The planet carrierassembly 1826 includes a plurality of pinion gears 1827 rotatablymounted on a carrier member 1829 and disposed in meshing relationshipwith both the sun gear member 1822 and the ring gear member 1824.

The planetary gear set 1830 includes a sun gear member 1832, a ring gearmember 1834, and a planet carrier assembly member 1836. The planetcarrier assembly member 1836 includes a plurality of pinion gears 1837rotatably mounted on a carrier member 1839 and disposed in meshingrelationship with both the sun gear member 1832 and the ring gear member1834.

The planetary gear set 1840 includes a sun gear member 1842, a ring gearmember 1844, and a planet carrier assembly member 1846. The planetcarrier assembly member 1846 includes a plurality of pinion gears 1847rotatably mounted on a carrier member 1849 and disposed in meshingrelationship with both the sun gear member 1842 and the ring gear member1844.

The planetary gear arrangement 1818 also includes sixtorque-transmitting mechanisms 1850, 1852, 1854, 1856, 1858 and 1859.The torque-transmitting mechanisms 1850, 1852, 1854, 1856 and 1858 arerotating type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanism 1859 is a stationary-type torquetransmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member1842, and the output shaft 19 is continuously connected with the ringgear member 1834. The ring gear member 1824 is continuously connectedwith the sun gear member 1832 through the interconnecting member 1870.The ring gear member 1844 is continuously connected with thetransmission housing 1860.

The ring gear member 1824 is selectively connectable with the planetcarrier assembly member 1846 through the clutch 1850. The sun gearmember 1822 is selectively connectable with the planet carrier assemblymember 1836 through the clutch 1852. The sun gear member 1822 isselectively connectable with the sun gear member 1842 through the clutch1854. The planet carrier assembly member 1826 is selectively connectablewith the planet carrier assembly member 1836 through the clutch 1856.The planet carrier assembly member 1826 is selectively connectable withthe planet carrier assembly member 1846 through the clutch 1858. The sungear member 1822 is selectively connectable with the transmissionhousing 1860 through the brake 1859.

The truth table shown in FIG. 19b defines the torque-transmittingmechanism engagement sequence that provides the reverse speed ratio andeight forward speed ratios shown in the truth table and available withthe planetary gear arrangement 1818. The truth table indicates that thetorque-transmitting mechanisms 1850 and 1859 can remain engaged throughthe neutral condition, thereby simplifying the forward/reverseinterchange. A sample of numerical values for the individual ratios isalso given in the truth table of FIG. 19b. These numerical values havebeen calculated using the ring gear/sun gear tooth ratios also given byway of example in FIG. 19b. The R1/S1 value is the tooth ratio of theplanetary gear set 1820; the R2/S2 value is the tooth ratio of theplanetary gear set 1830; and the R3/S3 value is the tooth ratio of theplanetary gear set 1840. FIG. 19b also describes the ratio steps betweenadjacent forward ratios and between the reverse and first forward ratiofor seven-speed and eight-speed transmissions. For example, the ratiostep between the first and second forward ratios is 1.66.

Those skilled in the art of planetary transmissions will recognize thatthe numerical values of the reverse and seventh forward speed ratios aredetermined utilizing the ring gear/sun gear tooth ratios of theplanetary gear sets 1830 and 1840. The numerical values of the first,second, fourth, fifth and eighth forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1820, 1830 and 1840. The numerical value of the third forward speedratio is determined utilizing the ring gear/sun gear tooth ratio of theplanetary gear set 1840. The numerical value of the sixth forward speedratio is one.

The powertrain 1910, shown in FIG. 20a, includes the conventional engineand torque converter 12, a planetary transmission 1914, and theconventional final drive mechanism 16. The engine and torque converter12 are drivingly connected with the planetary transmission 1914 throughthe input shaft 17. The planetary transmission 1914 is drivinglyconnected with the final drive mechanism 16 through the output shaft 19.The planetary transmission 1914 includes a planetary gear arrangement1918 that has a first planetary gear set 1920, a second planetary gearset 1930, and a third planetary gear set 1940.

The planetary gear set 1920 includes a sun gear member 1922, a ring gearmember 1924, and a planet carrier assembly 1926. The planet carrierassembly 1926 includes a plurality of pinion gears 1927 that arerotatably mounted on a carrier member 1929 and disposed in meshingrelationship with the sun gear member 1922 and the ring gear member1924, respectively.

The planetary gear set 1930 includes a sun gear member 1932, a ring gearmember 1934, and a planet carrier assembly member 1936. The planetcarrier assembly member 1936 includes a plurality of pinion gears 1937rotatably mounted on a carrier member 1939 and disposed in meshingrelationship with both the sun gear member 1932 and the ring gear member1934.

The planetary gear set 1940 includes a sun gear member 1942, a ring gearmember 1944, and a planet carrier assembly member 1946. The planetcarrier assembly member 1946 includes a plurality of pinion gears 1947rotatably mounted on a carrier member 1949 and disposed in meshingrelationship with both the sun gear member 1942 and the ring gear member1944.

The planetary gear arrangement 1918 also includes sixtorque-transmitting mechanisms 1950, 1952, 1954, 1956, 1958 and 1959.The torque-transmitting mechanisms 1950, 1952, 1954, 1956 and 1958 arerotating type torque-transmitting mechanisms, commonly termed clutches.The torque-transmitting mechanism 1959 is a stationary-type torquetransmitting mechanism, commonly termed brake or reaction clutch.

The input shaft 17 is continuously connected with the sun gear member1942, and the output shaft 19 is continuously connected with the planetcarrier assembly member 1926. The planet carrier assembly member 1926 iscontinuously connected with the ring gear member 1934 through theinterconnecting member 1970. The ring gear member 1944 is continuouslyconnected with the transmission housing 1960.

The sun gear member 1922 is selectively connectable with the planetcarrier assembly member 1936 through the clutch 1950. The ring gearmember 1924 is selectively connectable with the planet carrier assemblymember 1936 through the clutch 1952. The ring gear member 1924 isselectively connectable with the sun gear member 1942 through the clutch1954. The sun gear member 1932 is selectively connectable with theplanet carrier assembly member 1946 through the clutch 1956. The planetcarrier assembly member 1936 is selectively connectable with the planetcarrier assembly member 1946 through the clutch 1958. The sun gearmember 1922 is selectively connectable with the transmission housing1960 through the brake 1959.

The truth table of FIG. 20b describes the torque-transmitting mechanismengagement sequence utilized to provide the reverse speed ratio andeight forward speed ratios. The truth table also provides a set ofexamples for the ratios for each of the reverse and forward speedratios. These numerical values have been determined utilizing the ringgear/sun gear tooth ratios given in FIG. 20b. The R1/S1 value is thetooth ratio of the planetary gear set 1920; the R2/S2 value is the toothratio of the planetary gear set 1930; and the R3/S3 value is the toothratio of the planetary gear set 1940. Ratio spreads are also providedfor seven-speed and eight-speed transmissions.

Those skilled in the art, upon reviewing the engagement combinations,will recognize that the numerical values of the reverse and eighthforward speed ratios are determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 1930 and 1940. The numericalvalues of the first and sixth forward speed ratios are determinedutilizing the ring gear/sun gear tooth ratios of the planetary gear sets1920, 1930 and 1940. The numerical values of the second and fifthforward speed ratios are determined utilizing the ring gear/sun geartooth ratios of the planetary gear sets 1920 and 1940. The numericalvalue of the third forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 1940. The numericalvalue of the fourth forward speed ratio is determined utilizing the ringgear/sun gear tooth ratio of the planetary gear set 1920. The numericalvalue of the seventh forward speed ratio is one.

While the best modes for carrying out the invention have been describedin detail, those familiar with the art to which this invention relateswill recognize various alternative designs and embodiments forpracticing the invention within the scope of the appended claims.

What is claimed is:
 1. A transmission comprising: an input shaft; anoutput shaft; first, second and third planetary gear sets each havingfirst, second and third members; said input shaft being continuouslyinterconnected with a member of said planetary gear sets, and saidoutput shaft being continuously interconnected with another member ofsaid planetary gear sets; a first interconnecting member continuouslyinterconnecting said first member of said first planetary gear set withsaid first member of said second planetary gear set; said first memberof said third planetary gear set being continuously connected with astationary member; a first torque-transmitting mechanism selectivelyinterconnecting a member of said first planetary gear set with a memberof said third planetary gear set; a second torque-transmitting mechanismselectively interconnecting a member of said second planetary gear setwith a member of said third planetary gear set; a thirdtorque-transmitting mechanism selectively interconnecting a member ofsaid third planetary gear set with a member of said second planetarygear set, the pair of members interconnected by said thirdtorque-transmitting mechanism being different from the pair of membersinterconnected by said second torque-transmitting mechanism; a fourthtorque-transmitting mechanism selectively interconnecting a member ofsaid first planetary gear set with a member of said second or thirdplanetary gear set, the pair of members interconnected by said fourthtorque-transmitting mechanism being different from the pair of membersinterconnected by said first torque-transmitting mechanism; a fifthtorque-transmitting mechanism selectively interconnecting a member ofsaid first planetary gear set with a member of said second or thirdplanetary gear set or with said stationary member, the pair of membersinterconnected by said fifth torque-transmitting mechanism beingdifferent from the pairs of members interconnected by said first andfourth torque-transmitting mechanisms, respectively; and a sixthtorque-transmitting mechanism selectively interconnecting a member ofsaid first, second or third planetary gear set with another member ofsaid first or third planetary gear set, or with said stationary member,the pair of members interconnected by said sixth torque-transmittingmechanism being different from the pairs of members interconnected bysaid first, second, third, fourth and fifth torque-transmittingmechanisms, respectively; said torque-transmitting mechanisms beingengaged in combinations of three to establish at least seven forwardspeed ratios and at least one reverse speed ratio between said inputshaft and said output shaft.
 2. The transmission defined in claim 1,wherein said first, second, third, fourth and fifth torque-transmittingmechanisms comprise clutches, wherein said sixth torque-transmittingmechanism selectively interconnects said member of said first, second orthird planetary gear set with said stationary member and said sixthtorque-transmitting mechanism comprises a brake.
 3. The transmissiondefined in claim 1, wherein said first, second, third and fourthtorque-transmitting mechanisms comprise clutches, wherein said fifthtorque-transmitting mechanism selectively interconnects said member ofsaid first planetary gear set with said stationary member, wherein saidsixth torque-transmitting mechanism selectively interconnects saidmember of said first, second or third planetary gear set with saidstationary member and said fifth and sixth torque-transmittingmechanisms comprise brakes.
 4. The transmission defined in claim 1,wherein said first, second, third, fourth, fifth and sixthtorque-transmitting mechanisms comprise clutches.
 5. The transmissiondefined in claim 1, wherein each of said planetary gear sets includes aplanet carrier assembly member, and wherein said planet carrier assemblymember of each of said planetary gear sets is a single-pinion carrier.6. The transmission defined in claim 1, wherein each of said planetarygear sets includes a planet carrier assembly member, and wherein atleast one planet carrier assembly member of one of said planetary gearsets is a double-pinion carrier.
 7. A transmission comprising: an inputshaft; an output shaft; a planetary gear arrangement having first,second and third planetary gear sets, each planetary gear set havingfirst, second and third members; said input shaft being continuouslyinterconnected with a member of said planetary gear sets, and saidoutput shaft being continuously interconnected with another member ofsaid planetary gear sets; a first interconnecting member continuouslyinterconnecting said first member of said first planetary gear set withsaid first member of said second planetary gear set; said first memberof said third planetary gear set being continuously interconnected witha stationary member; and six torque-transmitting mechanisms forselectively interconnecting said members of said first, second or thirdplanetary gear sets with said stationary member or in pairs for commonrotation, said six torque-transmitting mechanisms being engaged incombinations of three to establish at least seven forward speed ratiosand one reverse speed ratio between said input shaft and said outputshaft.
 8. The transmission defined in claim 7, wherein a first of saidsix torque-transmitting mechanisms is operable for selectivelyinterconnecting a member of said first planetary gear set with a memberof said third planetary gear set.
 9. The transmission defined in claim7, wherein a second of said six torque-transmitting mechanisms isoperable for selectively interconnecting a member of said secondplanetary gear set with a member of said third planetary gear set. 10.The transmission defined in claim 7, wherein a third of said sixtorque-transmitting mechanisms is operable for selectivelyinterconnecting a member of said third planetary gear set with a memberof said second planetary gear set, the pair of members interconnected bysaid third torque-transmitting mechanism being different from the pairof members interconnected by a second of said six torque-transmittingmechanisms.
 11. The transmission defined in claim 7, wherein a fourth ofsaid six torque-transmitting mechanisms is operable for selectivelyinterconnecting a member of said first planetary gear set with a memberof said second or third planetary gear set, the pair of membersinterconnected by said fourth torque-transmitting mechanism beingdifferent from the pair of members interconnected by a first of said sixtorque-transmitting mechanisms.
 12. The transmission defined in claim 7,wherein a fifth of said six torque-transmitting mechanisms is operablefor selectively interconnecting a member of said first planetary gearset with a member of said second or third planetary gear set or withsaid stationary member, the pair of members interconnected by said fifthtorque-transmitting mechanism being different from the pairs of membersinterconnected by a first and a fourth of said six torque-transmittingmechanisms, respectively.
 13. The transmission defined in claim 7,wherein a sixth of said six torque-transmitting mechanisms is operablefor selectively interconnecting a member of said first, second or thirdplanetary gear set with another member of said first, second or thirdplanetary gear set or with said stationary member, the pair of membersinterconnected by said sixth torque-transmitting mechanism beingdifferent from the pairs of members interconnected by a first, second,third, fourth and fifth of said six torque-transmitting mechanisms,respectively.
 14. The transmission defined in claim 7, wherein each ofsaid planetary gear sets includes a planet carrier assembly member, andwherein said planet carrier assembly member of each of said planetarygear sets is a single-pinion carrier.
 15. The transmission in claim 7,wherein each of said planetary gear sets includes a planet carrierassembly member, and wherein at least one planet carrier assembly memberof one of said planetary gear sets is a double-pinion carrier.